update translations

When more than one printer is connected, ptouch-print used the first
one it found. --serial <serial> now uses only the printer with that USB
serial number, and --list-connected lists the connected printers with
their serials.

libptouch gets ptouch_open_serial() and ptouch_list_connected();
ptouch_open() keeps its signature and calls ptouch_open_serial() with
NULL. The serial is checked before the P-Lite and unsupported-raster
checks, so a different printer in the wrong mode no longer ends the
search, and the "found on USB bus" line now shows the serial. The early
error returns in the open loop now free the device list.

CMakeLists.txt

@@ -15,6 +15,11 @@ find_package(Git REQUIRED)
 find_package(PkgConfig REQUIRED)
 find_package(Intl REQUIRED)
 find_package(argp REQUIRED)
+if(NOT ARGP_IN_LIBC AND NOT HAVE_STRCHRNUL)
+	# See cmake/Findargp.cmake: argp-standalone needs a strchrnul() the
+	# platform does not have, so ptouch-print.c defines one.
+	add_compile_definitions(NEED_STRCHRNUL=1)
+endif()
 
 pkg_check_modules(LIBUSB REQUIRED libusb-1.0)
 
@@ -32,7 +37,6 @@ target_include_directories(${PROJECT_NAME} PUBLIC
 
 target_link_libraries(${PROJECT_NAME} PRIVATE
 	${GD_LIBRARIES}
-	${LIBUSB_LIBRARIES}
 	${LIBUSB_LINK_LIBRARIES}
 	${Intl_LIBRARIES}
 	${ARGP_LIBRARIES}

cmake/Findargp.cmake

@@ -62,9 +62,33 @@ if (ARGP_INCLUDE_PATH)
 
     # Check if argp_parse is available. Some implementations don't have this
     # symbol defined, thus they're not compatible.
+    #
+    # argp-standalone itself calls strchrnul(), a GNU extension that the
+    # platforms needing argp-standalone tend to lack (macOS among them). On
+    # those the plain link test fails with an undefined strchrnul and would
+    # report a perfectly good libargp as lacking argp_parse. So probe for
+    # strchrnul first and, where it is missing, run the argp_parse test with
+    # a local definition; the project then supplies the same definition.
     if (ARGP_LIBRARIES)
         set(CMAKE_REQUIRED_LIBRARIES "${ARGP_LIBRARIES}")
-        check_function_exists("argp_parse" ARGP_EXTERNAL)
+        include(CheckSymbolExists)
+        set(CMAKE_REQUIRED_DEFINITIONS -D_GNU_SOURCE)
+        check_symbol_exists("strchrnul" "string.h" HAVE_STRCHRNUL)
+        unset(CMAKE_REQUIRED_DEFINITIONS)
+        if (HAVE_STRCHRNUL)
+            check_function_exists("argp_parse" ARGP_EXTERNAL)
+        else ()
+            include(CheckCSourceCompiles)
+            check_c_source_compiles("
+                #include <string.h>
+                #include <argp.h>
+                char *strchrnul(const char *s, int c) {
+                    const char *p = strchr(s, c);
+                    return (char *)(p ? p : s + strlen(s));
+                }
+                int main(void) { return argp_parse(0, 1, (char *[]){\"x\"}, 0, 0, 0); }
+            " ARGP_EXTERNAL)
+        endif ()
         if (NOT ARGP_EXTERNAL)
             message(FATAL_ERROR "Your system ships an argp library in "
                     "${ARGP_LIBRARIES}, but it does not have a symbol "

include/ptouch.h

@@ -1,7 +1,7 @@
 /*
 	ptouch-print - Print labels with images or text on a Brother P-Touch
 
-	Copyright (C) 2015-2023 Dominic Radermacher <dominic@familie-radermacher.ch>
+	Copyright (C) 2015-2026 Dominic Radermacher <dominic@familie-radermacher.ch>
 
 	This program is free software; you can redistribute it and/or modify it
 	under the terms of the GNU General Public License version 3 as
@@ -26,7 +26,8 @@
 
 struct _pt_tape_info {
 	uint8_t mm;		/* Tape width in mm */
-	uint16_t px;		/* Printing area in px */
+	uint16_t px;		/* Printing area in px at 180 dpi */
+	uint16_t px360;		/* Printing area in px at 360 dpi */
 	double margins;		/* default tape margins in mm */
 };
 
@@ -56,6 +57,15 @@ struct _pt_dev_info {
 	int dpi;		/* Dots per inch of the printhead */
 	//size_t bytes_per_line;
 	int flags;
+	/* Pins to shift the print area from the centre of the printhead.
+	   On some models the print area is not centred on the head; see the
+	   Brother "Software Developer's Manual - Raster Command Reference,
+	   PT-P900/P900W/P950NW", section 2.3.5 "Raster line". 0 = centred. */
+	int pin_offset;
+	/* Seconds to wait for a status response when the user did not ask for a
+	   particular --timeout. 0 means use the global default; a printer only
+	   needs an entry here if the global default is too short for it. */
+	int min_timeout;
 };
 typedef struct _pt_dev_info *pt_dev_info;
 
@@ -97,13 +107,17 @@ struct _ptouch_dev {
 typedef struct _ptouch_dev *ptouch_dev;
 
 int ptouch_open(ptouch_dev *ptdev);
+int ptouch_open_serial(ptouch_dev *ptdev, const char *serial);
 int ptouch_close(ptouch_dev ptdev);
 int ptouch_send(ptouch_dev ptdev, uint8_t *data, size_t len);
 int ptouch_init(ptouch_dev ptdev);
 int ptouch_lf(ptouch_dev ptdev);
 int ptouch_ff(ptouch_dev ptdev);
+int ptouch_get_dpi(ptouch_dev ptdev);
+int ptouch_calc_tape_px(ptouch_dev ptdev, const uint8_t tape_with_mm);
 size_t ptouch_get_max_width(ptouch_dev ptdev);
 size_t ptouch_get_tape_width(ptouch_dev ptdev);
+int ptouch_get_max_lines(ptouch_dev ptdev, int fontsize_px);
 int ptouch_page_flags(ptouch_dev ptdev, uint8_t page_flags);
 int ptouch_finalize(ptouch_dev ptdev, int chain);
 int ptouch_getstatus(ptouch_dev ptdev, int timeout);
@@ -117,6 +131,7 @@ int ptouch_rasterstart(ptouch_dev ptdev);
 int ptouch_sendraster(ptouch_dev ptdev, uint8_t *data, size_t len);
 void ptouch_rawstatus(uint8_t raw[32]);
 void ptouch_list_supported();
+int ptouch_list_connected();
 
 const char* pt_mediatype(unsigned char media_type);
 const char* pt_tapecolor(unsigned char tape_color);

po/de.po

@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: ptouch-print 1.7\n"
 "Report-Msgid-Bugs-To: dominic@familie-radermacher.ch\n"
-"POT-Creation-Date: 2026-03-06 08:07+0100\n"
+"POT-Creation-Date: 2026-09-25 09:51+0200\n"
 "PO-Revision-Date: 2024-05-23 22:27-0400\n"
 "Last-Translator: dominic@familie-radermacher.ch\n"
 "Language-Team: German <translation-team-de@lists.sourceforge.net>\n"
@@ -19,289 +19,351 @@ msgstr ""
 "Plural-Forms: nplurals=2; plural=(n != 1);\n"
 "X-Generator: Poedit 2.4.2\n"
 
-#: src/libptouch.c:108 src/libptouch.c:112 src/libptouch.c:116
+#: src/libptouch.c:131 src/libptouch.c:135 src/libptouch.c:139
 #, c-format
 msgid "out of memory\n"
 msgstr "Nicht genug Speicher\n"
 
-#: src/libptouch.c:120
+#: src/libptouch.c:143 src/libptouch.c:602
 #, c-format
 msgid "libusb_init() failed\n"
 msgstr "ptouch_init() fehlgeschlagen\n"
 
-#: src/libptouch.c:129
+#: src/libptouch.c:152
 #, c-format
 msgid "failed to get device descriptor"
 msgstr ""
 
-#: src/libptouch.c:135
+#: src/libptouch.c:160
-#, c-format
-msgid "%s found on USB bus %d, device %d\n"
-msgstr "Drucker %s am USB Bus %d, Gerät %d gefunden\n"
-
-#: src/libptouch.c:150
 #, c-format
 msgid "libusb_open error :%s\n"
 msgstr ""
 
-#: src/libptouch.c:156
+#: src/libptouch.c:171
+#, fuzzy, c-format
+msgid "%s found on USB bus %d, device %d, serial %s\n"
+msgstr "Drucker %s am USB Bus %d, Gerät %d gefunden\n"
+
+#: src/libptouch.c:200
 #, c-format
 msgid "error while detaching kernel driver: %s\n"
 msgstr ""
 
-#: src/libptouch.c:160
+#: src/libptouch.c:204
 #, c-format
 msgid "interface claim error: %s\n"
 msgstr ""
 
-#: src/libptouch.c:171
+#: src/libptouch.c:218
+#, c-format
+msgid "No P-Touch printer with serial %s found\n"
+msgstr ""
+
+#: src/libptouch.c:220 src/ptouch-print.c:722
 #, c-format
 msgid ""
 "No P-Touch printer found on USB (remember to put switch to position E)\n"
 msgstr "Kein P-Ptouch Drucker am USB gefunden (Schalter muss auf E stehen)\n"
 
-#: src/libptouch.c:191
+#: src/libptouch.c:241
 #, c-format
 msgid "debug: called ptouch_send() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:198
+#: src/libptouch.c:248
 #, c-format
 msgid "write error: %s\n"
 msgstr ""
 
-#: src/libptouch.c:202
+#: src/libptouch.c:252
 #, fuzzy, c-format
 msgid "write error: could send only %i of %ld bytes\n"
 msgstr "Lesefehler: %i anstatt 32 bytes empfangen\n"
 
-#: src/libptouch.c:252
+#: src/libptouch.c:302
 #, c-format
 msgid "debug: called ptouch_info_cmd() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:294
+#: src/libptouch.c:344
 #, fuzzy, c-format
 msgid "debug: called ptouch_rasterstart() with NULL ptdev\n"
 msgstr "ptouch_rasterstart() fehlgeschlagen\n"
 
-#: src/libptouch.c:325
+#: src/libptouch.c:384
 #, c-format
 msgid "debug: called ptouch_finalize() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:340
+#: src/libptouch.c:399
 #, c-format
 msgid "debug: dumping raw status bytes\n"
 msgstr ""
 
-#: src/libptouch.c:359
+#: src/libptouch.c:418
 #, c-format
 msgid "debug: called ptouch_getstatus() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:369 src/libptouch.c:405
+#: src/libptouch.c:428 src/libptouch.c:459
 #, c-format
 msgid "read error: %s\n"
 msgstr ""
 
-#: src/libptouch.c:374
+#: src/libptouch.c:433
 #, c-format
 msgid "timeout (%i sec) while waiting for status response\n"
 msgstr ""
 
-#: src/libptouch.c:388
+#: src/libptouch.c:442
 #, c-format
 msgid "unknown tape width of %imm, please report this.\n"
 msgstr "Unbekannte Schriftband breite (%i mm), bitte melden\n"
 
-#: src/libptouch.c:394
+#: src/libptouch.c:448
 #, c-format
 msgid "got only 16 bytes... wondering what they are:\n"
 msgstr "nur 16 bytes empfangen... mal gucken was die sind:\n"
 
-#: src/libptouch.c:398
+#: src/libptouch.c:452
 #, c-format
 msgid "read error: got %i instead of 32 bytes\n"
 msgstr "Lesefehler: %i anstatt 32 bytes empfangen\n"
 
-#: src/libptouch.c:401
+#: src/libptouch.c:455
 #, c-format
 msgid "strange status:\n"
 msgstr "Seltsamer Status:\n"
 
-#: src/libptouch.c:403
+#: src/libptouch.c:457
 #, c-format
 msgid "trying to flush junk\n"
 msgstr ""
 
-#: src/libptouch.c:408
+#: src/libptouch.c:462
 #, c-format
 msgid "got another %i bytes. now try again\n"
 msgstr "weitere %i bytes empfangen. probiere es nochmal.\n"
 
-#: src/libptouch.c:415
+#: src/libptouch.c:469
+#, fuzzy, c-format
+msgid "debug: called ptouch_get_dpi() with NULL ptdev\n"
+msgstr "ptouch_rasterstart() fehlgeschlagen\n"
+
+#: src/libptouch.c:478
+#, fuzzy, c-format
+msgid "debug: called ptouch_cal_tape_width() with NULL ptdev\n"
+msgstr "ptouch_rasterstart() fehlgeschlagen\n"
+
+#: src/libptouch.c:489
+#, c-format
+msgid "printer with %d dpi not supported\n"
+msgstr ""
+
+#: src/libptouch.c:509
+#, fuzzy, c-format
+msgid "debug: called ptouch_get_max_lines() with NULL ptdev\n"
+msgstr "ptouch_rasterstart() fehlgeschlagen\n"
+
+#: src/libptouch.c:513
+#, fuzzy, c-format
+msgid "debug: called ptouch_get_max_lines() with invalid fontsize_px\n"
+msgstr "ptouch_rasterstart() fehlgeschlagen\n"
+
+#: src/libptouch.c:516
+#, c-format
+msgid "debug: calculated max lines %d \n"
+msgstr ""
+
+#: src/libptouch.c:523
 #, c-format
 msgid "debug: called ptouch_get_tape_width() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:424
+#: src/libptouch.c:532
 #, c-format
 msgid "debug: called ptouch_get_max_width() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:436
+#: src/libptouch.c:547
 #, c-format
 msgid "debug: called ptouch_sendraster() with NULL ptdev\n"
 msgstr ""
 
-#: src/ptouch-print.c:153
+#: src/libptouch.c:625
+#, fuzzy, c-format
+msgid "%s\tserial %s\t(USB bus %d, device %d)%s\n"
+msgstr "Drucker %s am USB Bus %d, Gerät %d gefunden\n"
+
+#: src/libptouch.c:629
+msgid " - in P-Lite mode, unsupported"
+msgstr ""
+
+#: src/libptouch.c:630
+msgid " - unsupported"
+msgstr ""
+
+#: src/ptouch-print.c:190
 #, c-format
 msgid "nothing to print\n"
 msgstr ""
 
-#: src/ptouch-print.c:161
+#: src/ptouch-print.c:198
 #, c-format
 msgid "image is too large (%ipx x %ipx)\n"
 msgstr "Bild ist zu gross (%ipx x %ipx)\n"
 
-#: src/ptouch-print.c:162
+#: src/ptouch-print.c:199
 #, c-format
 msgid "maximum printing width for this tape is %ipx\n"
 msgstr "Maximal druckbare Breite für dieses Schriftband sind %ipx\n"
 
-#: src/ptouch-print.c:165
+#: src/ptouch-print.c:202
 #, fuzzy, c-format
 msgid "image size (%ipx x %ipx)\n"
 msgstr "Bild ist zu gross (%ipx x %ipx)\n"
 
-#: src/ptouch-print.c:175
+#: src/ptouch-print.c:218
 #, c-format
 msgid "ptouch_rasterstart() failed\n"
 msgstr "ptouch_rasterstart() fehlgeschlagen\n"
 
-#: src/ptouch-print.c:181
+#: src/ptouch-print.c:224
 #, c-format
 msgid "send print information command\n"
 msgstr ""
 
-#: src/ptouch-print.c:187
+#: src/ptouch-print.c:230
 #, c-format
 msgid "send PT-D460BT magic commands\n"
 msgstr ""
 
-#: src/ptouch-print.c:194
+#: src/ptouch-print.c:237
 #, c-format
 msgid "send precut command\n"
 msgstr ""
 
-#: src/ptouch-print.c:203
+#: src/ptouch-print.c:246
 #, c-format
 msgid "send PT-D460BT chain commands\n"
 msgstr ""
 
-#: src/ptouch-print.c:215
+#: src/ptouch-print.c:258
 #, fuzzy, c-format
 msgid "ptouch_sendraster() failed\n"
 msgstr "ptouch_send() fehlgeschlagen\n"
 
-#: src/ptouch-print.c:264
+#: src/ptouch-print.c:307
 #, c-format
 msgid "writing image '%s' failed\n"
 msgstr "Schreiben der Bilddatei '%s' fehlgeschlagen\n"
 
-#: src/ptouch-print.c:286
+#: src/ptouch-print.c:312
 #, c-format
-msgid "debug: o baseline offset - %d\n"
+msgid "printing '%s' requires %.1f mm of tape\n"
 msgstr ""
 
-#: src/ptouch-print.c:287
+#: src/ptouch-print.c:334
+#, c-format
+msgid "debug: z baseline offset - %d\n"
+msgstr ""
+
+#: src/ptouch-print.c:335
 #, c-format
 msgid "debug: text baseline offset - %d\n"
 msgstr ""
 
-#: src/ptouch-print.c:346
+#: src/ptouch-print.c:408
 #, c-format
 msgid "render_text(): %i lines, font = '%s', align = '%c'\n"
 msgstr ""
 
-#: src/ptouch-print.c:349
+#: src/ptouch-print.c:411
 #, c-format
 msgid "warning: font config not available\n"
 msgstr "Warnung: fontconfig ist nicht verfügbar\n"
 
-#: src/ptouch-print.c:353
+#: src/ptouch-print.c:415
 #, c-format
 msgid "setting font size=%i\n"
 msgstr "setze Zeichensatzgrösse=%i\n"
 
-#: src/ptouch-print.c:357
+#: src/ptouch-print.c:417
+#, fuzzy, c-format
+msgid "ignoring setting font margin=%i\n"
+msgstr "setze Zeichensatzgrösse=%i\n"
+
+#: src/ptouch-print.c:422
 #, c-format
 msgid "could not estimate needed font size\n"
 msgstr "Konnte die notwendige Zeichensatzgrösse nicht bestimmen\n"
 
-#: src/ptouch-print.c:364
+#: src/ptouch-print.c:429
 #, c-format
 msgid "choosing font size=%i\n"
 msgstr "Wähle Zeichensatzgrösse %i\n"
 
-#: src/ptouch-print.c:380 src/ptouch-print.c:414
+#: src/ptouch-print.c:445 src/ptouch-print.c:479
-#, c-format
+#, fuzzy, c-format
-msgid "error in gdImageStringFT: %s\n"
+msgid "error in gdImageStringFT_180dpi: %s\n"
 msgstr "Fehler in Funktion gdImageStringFT(): %s\n"
 
-#: src/ptouch-print.c:571
+#: src/ptouch-print.c:636
 #, c-format
 msgid "Only up to %d lines are supported"
 msgstr ""
 
-#: src/ptouch-print.c:649
+#: src/ptouch-print.c:727
 msgid "No arguments supported"
 msgstr ""
 
-#: src/ptouch-print.c:654
+#: src/ptouch-print.c:732
 msgid "Option --writepng missing"
 msgstr ""
 
-#: src/ptouch-print.c:657
+#: src/ptouch-print.c:735
 msgid "Options --force_tape_width and --info can't be used together"
 msgstr ""
 
-#: src/ptouch-print.c:688
+#: src/ptouch-print.c:766
 #, c-format
 msgid "ptouch_init() failed\n"
 msgstr "ptouch_init() fehlgeschlagen\n"
 
-#: src/ptouch-print.c:691
+#: src/ptouch-print.c:775
 #, c-format
 msgid "ptouch_getstatus() failed\n"
 msgstr "ptouch_getstatus() fehlgeschlagen\n"
 
-#: src/ptouch-print.c:705
+#: src/ptouch-print.c:789
 #, fuzzy, c-format
-msgid "maximum printing width for this printer is %ldpx\n"
+msgid "printer has %d dpi, maximum printing width is %ld px\n"
 msgstr "Maximal druckbare Breite für dieses Schriftband sind %ipx\n"
 
-#: src/ptouch-print.c:706
+#: src/ptouch-print.c:790
 #, fuzzy, c-format
 msgid "maximum printing width for this tape is %ldpx\n"
 msgstr "Maximal druckbare Breite für dieses Schriftband sind %ipx\n"
 
-#: src/ptouch-print.c:731
+#: src/ptouch-print.c:815
 #, c-format
 msgid "failed to load image file\n"
 msgstr ""
 
-#: src/ptouch-print.c:740
+#: src/ptouch-print.c:824
 #, c-format
 msgid "could not render text\n"
 msgstr "Konnte Text nicht rendern\n"
 
-#: src/ptouch-print.c:779
+#: src/ptouch-print.c:865
 #, c-format
 msgid "ptouch_finalize(%d) failed\n"
 msgstr "ptouch_finalize(%d) fehlgeschlagen\n"
 
+#, fuzzy, c-format
+#~ msgid "maximum printing width for this printer is %ldpx\n"
+#~ msgstr "Maximal druckbare Breite für dieses Schriftband sind %ipx\n"
+
 #, c-format
 #~ msgid "ptouch-print version %s by Dominic Radermacher\n"
 #~ msgstr "ptouch-print Version %s von Dominic Radermacher\n"

po/en.po

@@ -7,7 +7,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: ptouch-print 1.7\n"
 "Report-Msgid-Bugs-To: dominic@familie-radermacher.ch\n"
-"POT-Creation-Date: 2026-03-06 08:07+0100\n"
+"POT-Creation-Date: 2026-09-25 09:51+0200\n"
 "PO-Revision-Date: 2024-05-23 22:26-0400\n"
 "Last-Translator: dominic@familie-radermacher.ch\n"
 "Language-Team: English <en@translate.freefriends.org>\n"
@@ -18,290 +18,352 @@ msgstr ""
 "Plural-Forms: nplurals=2; plural=(n != 1);\n"
 "X-Generator: Poedit 2.4.2\n"
 
-#: src/libptouch.c:108 src/libptouch.c:112 src/libptouch.c:116
+#: src/libptouch.c:131 src/libptouch.c:135 src/libptouch.c:139
 #, c-format
 msgid "out of memory\n"
 msgstr "out of memory\n"
 
-#: src/libptouch.c:120
+#: src/libptouch.c:143 src/libptouch.c:602
 #, c-format
 msgid "libusb_init() failed\n"
 msgstr "libusb_init() failed\n"
 
-#: src/libptouch.c:129
+#: src/libptouch.c:152
 #, c-format
 msgid "failed to get device descriptor"
 msgstr "failed to get device descriptor"
 
-#: src/libptouch.c:135
+#: src/libptouch.c:160
-#, c-format
-msgid "%s found on USB bus %d, device %d\n"
-msgstr "%s found on USB bus %d, device %d\n"
-
-#: src/libptouch.c:150
 #, c-format
 msgid "libusb_open error :%s\n"
 msgstr "libusb_open error :%s\n"
 
-#: src/libptouch.c:156
+#: src/libptouch.c:171
+#, fuzzy, c-format
+msgid "%s found on USB bus %d, device %d, serial %s\n"
+msgstr "%s found on USB bus %d, device %d\n"
+
+#: src/libptouch.c:200
 #, c-format
 msgid "error while detaching kernel driver: %s\n"
 msgstr "error while detaching kernel driver: %s\n"
 
-#: src/libptouch.c:160
+#: src/libptouch.c:204
 #, c-format
 msgid "interface claim error: %s\n"
 msgstr "interface claim error: %s\n"
 
-#: src/libptouch.c:171
+#: src/libptouch.c:218
+#, c-format
+msgid "No P-Touch printer with serial %s found\n"
+msgstr ""
+
+#: src/libptouch.c:220 src/ptouch-print.c:722
 #, c-format
 msgid ""
 "No P-Touch printer found on USB (remember to put switch to position E)\n"
 msgstr ""
 "No P-Touch printer found on USB (remember to put switch to position E)\n"
 
-#: src/libptouch.c:191
+#: src/libptouch.c:241
 #, c-format
 msgid "debug: called ptouch_send() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:198
+#: src/libptouch.c:248
 #, c-format
 msgid "write error: %s\n"
 msgstr "write error: %s\n"
 
-#: src/libptouch.c:202
+#: src/libptouch.c:252
 #, fuzzy, c-format
 msgid "write error: could send only %i of %ld bytes\n"
 msgstr "write error: could send only %i of %i bytes\n"
 
-#: src/libptouch.c:252
+#: src/libptouch.c:302
 #, c-format
 msgid "debug: called ptouch_info_cmd() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:294
+#: src/libptouch.c:344
 #, fuzzy, c-format
 msgid "debug: called ptouch_rasterstart() with NULL ptdev\n"
 msgstr "ptouch_rasterstart() failed\n"
 
-#: src/libptouch.c:325
+#: src/libptouch.c:384
 #, c-format
 msgid "debug: called ptouch_finalize() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:340
+#: src/libptouch.c:399
 #, c-format
 msgid "debug: dumping raw status bytes\n"
 msgstr "debug: dumping raw status bytes\n"
 
-#: src/libptouch.c:359
+#: src/libptouch.c:418
 #, c-format
 msgid "debug: called ptouch_getstatus() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:369 src/libptouch.c:405
+#: src/libptouch.c:428 src/libptouch.c:459
 #, c-format
 msgid "read error: %s\n"
 msgstr "read error: %s\n"
 
-#: src/libptouch.c:374
+#: src/libptouch.c:433
 #, fuzzy, c-format
 msgid "timeout (%i sec) while waiting for status response\n"
 msgstr "timeout while waiting for status response\n"
 
-#: src/libptouch.c:388
+#: src/libptouch.c:442
 #, c-format
 msgid "unknown tape width of %imm, please report this.\n"
 msgstr "unknown tape width of %imm, please report this.\n"
 
-#: src/libptouch.c:394
+#: src/libptouch.c:448
 #, c-format
 msgid "got only 16 bytes... wondering what they are:\n"
 msgstr "got only 16 bytes... wondering what they are:\n"
 
-#: src/libptouch.c:398
+#: src/libptouch.c:452
 #, c-format
 msgid "read error: got %i instead of 32 bytes\n"
 msgstr "read error: got %i instead of 32 bytes\n"
 
-#: src/libptouch.c:401
+#: src/libptouch.c:455
 #, c-format
 msgid "strange status:\n"
 msgstr "strange status:\n"
 
-#: src/libptouch.c:403
+#: src/libptouch.c:457
 #, c-format
 msgid "trying to flush junk\n"
 msgstr "trying to flush junk\n"
 
-#: src/libptouch.c:408
+#: src/libptouch.c:462
 #, c-format
 msgid "got another %i bytes. now try again\n"
 msgstr "got another %i bytes. now try again\n"
 
-#: src/libptouch.c:415
+#: src/libptouch.c:469
+#, fuzzy, c-format
+msgid "debug: called ptouch_get_dpi() with NULL ptdev\n"
+msgstr "ptouch_rasterstart() failed\n"
+
+#: src/libptouch.c:478
+#, fuzzy, c-format
+msgid "debug: called ptouch_cal_tape_width() with NULL ptdev\n"
+msgstr "ptouch_rasterstart() failed\n"
+
+#: src/libptouch.c:489
+#, c-format
+msgid "printer with %d dpi not supported\n"
+msgstr ""
+
+#: src/libptouch.c:509
+#, fuzzy, c-format
+msgid "debug: called ptouch_get_max_lines() with NULL ptdev\n"
+msgstr "ptouch_rasterstart() failed\n"
+
+#: src/libptouch.c:513
+#, fuzzy, c-format
+msgid "debug: called ptouch_get_max_lines() with invalid fontsize_px\n"
+msgstr "ptouch_rasterstart() failed\n"
+
+#: src/libptouch.c:516
+#, c-format
+msgid "debug: calculated max lines %d \n"
+msgstr ""
+
+#: src/libptouch.c:523
 #, c-format
 msgid "debug: called ptouch_get_tape_width() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:424
+#: src/libptouch.c:532
 #, c-format
 msgid "debug: called ptouch_get_max_width() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:436
+#: src/libptouch.c:547
 #, c-format
 msgid "debug: called ptouch_sendraster() with NULL ptdev\n"
 msgstr ""
 
-#: src/ptouch-print.c:153
+#: src/libptouch.c:625
+#, fuzzy, c-format
+msgid "%s\tserial %s\t(USB bus %d, device %d)%s\n"
+msgstr "%s found on USB bus %d, device %d\n"
+
+#: src/libptouch.c:629
+msgid " - in P-Lite mode, unsupported"
+msgstr ""
+
+#: src/libptouch.c:630
+msgid " - unsupported"
+msgstr ""
+
+#: src/ptouch-print.c:190
 #, c-format
 msgid "nothing to print\n"
 msgstr ""
 
-#: src/ptouch-print.c:161
+#: src/ptouch-print.c:198
 #, c-format
 msgid "image is too large (%ipx x %ipx)\n"
 msgstr "image is too large (%ipx x %ipx)\n"
 
-#: src/ptouch-print.c:162
+#: src/ptouch-print.c:199
 #, c-format
 msgid "maximum printing width for this tape is %ipx\n"
 msgstr "maximum printing width for this tape is %ipx\n"
 
-#: src/ptouch-print.c:165
+#: src/ptouch-print.c:202
 #, fuzzy, c-format
 msgid "image size (%ipx x %ipx)\n"
 msgstr "image is too large (%ipx x %ipx)\n"
 
-#: src/ptouch-print.c:175
+#: src/ptouch-print.c:218
 #, c-format
 msgid "ptouch_rasterstart() failed\n"
 msgstr "ptouch_rasterstart() failed\n"
 
-#: src/ptouch-print.c:181
+#: src/ptouch-print.c:224
 #, c-format
 msgid "send print information command\n"
 msgstr ""
 
-#: src/ptouch-print.c:187
+#: src/ptouch-print.c:230
 #, c-format
 msgid "send PT-D460BT magic commands\n"
 msgstr ""
 
-#: src/ptouch-print.c:194
+#: src/ptouch-print.c:237
 #, c-format
 msgid "send precut command\n"
 msgstr ""
 
-#: src/ptouch-print.c:203
+#: src/ptouch-print.c:246
 #, c-format
 msgid "send PT-D460BT chain commands\n"
 msgstr ""
 
-#: src/ptouch-print.c:215
+#: src/ptouch-print.c:258
 #, c-format
 msgid "ptouch_sendraster() failed\n"
 msgstr "ptouch_sendraster() failed\n"
 
-#: src/ptouch-print.c:264
+#: src/ptouch-print.c:307
 #, c-format
 msgid "writing image '%s' failed\n"
 msgstr "writing image '%s' failed\n"
 
-#: src/ptouch-print.c:286
+#: src/ptouch-print.c:312
 #, c-format
-msgid "debug: o baseline offset - %d\n"
+msgid "printing '%s' requires %.1f mm of tape\n"
 msgstr ""
 
-#: src/ptouch-print.c:287
+#: src/ptouch-print.c:334
+#, c-format
+msgid "debug: z baseline offset - %d\n"
+msgstr ""
+
+#: src/ptouch-print.c:335
 #, c-format
 msgid "debug: text baseline offset - %d\n"
 msgstr ""
 
-#: src/ptouch-print.c:346
+#: src/ptouch-print.c:408
 #, c-format
 msgid "render_text(): %i lines, font = '%s', align = '%c'\n"
 msgstr ""
 
-#: src/ptouch-print.c:349
+#: src/ptouch-print.c:411
 #, c-format
 msgid "warning: font config not available\n"
 msgstr "warning: font config not available\n"
 
-#: src/ptouch-print.c:353
+#: src/ptouch-print.c:415
 #, c-format
 msgid "setting font size=%i\n"
 msgstr "setting font size=%i\n"
 
-#: src/ptouch-print.c:357
+#: src/ptouch-print.c:417
+#, fuzzy, c-format
+msgid "ignoring setting font margin=%i\n"
+msgstr "setting font size=%i\n"
+
+#: src/ptouch-print.c:422
 #, c-format
 msgid "could not estimate needed font size\n"
 msgstr "could not estimate needed font size\n"
 
-#: src/ptouch-print.c:364
+#: src/ptouch-print.c:429
 #, c-format
 msgid "choosing font size=%i\n"
 msgstr "choosing font size=%i\n"
 
-#: src/ptouch-print.c:380 src/ptouch-print.c:414
+#: src/ptouch-print.c:445 src/ptouch-print.c:479
-#, c-format
+#, fuzzy, c-format
-msgid "error in gdImageStringFT: %s\n"
+msgid "error in gdImageStringFT_180dpi: %s\n"
 msgstr "error in gdImageStringFT: %s\n"
 
-#: src/ptouch-print.c:571
+#: src/ptouch-print.c:636
 #, c-format
 msgid "Only up to %d lines are supported"
 msgstr ""
 
-#: src/ptouch-print.c:649
+#: src/ptouch-print.c:727
 msgid "No arguments supported"
 msgstr ""
 
-#: src/ptouch-print.c:654
+#: src/ptouch-print.c:732
 msgid "Option --writepng missing"
 msgstr ""
 
-#: src/ptouch-print.c:657
+#: src/ptouch-print.c:735
 msgid "Options --force_tape_width and --info can't be used together"
 msgstr ""
 
-#: src/ptouch-print.c:688
+#: src/ptouch-print.c:766
 #, c-format
 msgid "ptouch_init() failed\n"
 msgstr "ptouch_init() failed\n"
 
-#: src/ptouch-print.c:691
+#: src/ptouch-print.c:775
 #, c-format
 msgid "ptouch_getstatus() failed\n"
 msgstr "ptouch_getstatus() failed\n"
 
-#: src/ptouch-print.c:705
+#: src/ptouch-print.c:789
 #, fuzzy, c-format
-msgid "maximum printing width for this printer is %ldpx\n"
+msgid "printer has %d dpi, maximum printing width is %ld px\n"
 msgstr "maximum printing width for this tape is %ipx\n"
 
-#: src/ptouch-print.c:706
+#: src/ptouch-print.c:790
 #, fuzzy, c-format
 msgid "maximum printing width for this tape is %ldpx\n"
 msgstr "maximum printing width for this tape is %ipx\n"
 
-#: src/ptouch-print.c:731
+#: src/ptouch-print.c:815
 #, c-format
 msgid "failed to load image file\n"
 msgstr ""
 
-#: src/ptouch-print.c:740
+#: src/ptouch-print.c:824
 #, c-format
 msgid "could not render text\n"
 msgstr "could not render text\n"
 
-#: src/ptouch-print.c:779
+#: src/ptouch-print.c:865
 #, c-format
 msgid "ptouch_finalize(%d) failed\n"
 msgstr "ptouch_finalize(%d) failed\n"
 
+#, fuzzy, c-format
+#~ msgid "maximum printing width for this printer is %ldpx\n"
+#~ msgstr "maximum printing width for this tape is %ipx\n"
+
 #, c-format
 #~ msgid "ptouch-print version %s by Dominic Radermacher\n"
 #~ msgstr "ptouch-print version %s by Dominic Radermacher\n"

po/ptouch.pot

@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: ptouch-print\n"
 "Report-Msgid-Bugs-To: dominic@familie-radermacher.ch\n"
-"POT-Creation-Date: 2026-03-06 08:13+0100\n"
+"POT-Creation-Date: 2026-09-25 09:51+0200\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -17,285 +17,343 @@ msgstr ""
 "Content-Type: text/plain; charset=CHARSET\n"
 "Content-Transfer-Encoding: 8bit\n"
 
-#: src/libptouch.c:108 src/libptouch.c:112 src/libptouch.c:116
+#: src/libptouch.c:131 src/libptouch.c:135 src/libptouch.c:139
 #, c-format
 msgid "out of memory\n"
 msgstr ""
 
-#: src/libptouch.c:120
+#: src/libptouch.c:143 src/libptouch.c:602
 #, c-format
 msgid "libusb_init() failed\n"
 msgstr ""
 
-#: src/libptouch.c:129
+#: src/libptouch.c:152
 #, c-format
 msgid "failed to get device descriptor"
 msgstr ""
 
-#: src/libptouch.c:135
+#: src/libptouch.c:160
-#, c-format
-msgid "%s found on USB bus %d, device %d\n"
-msgstr ""
-
-#: src/libptouch.c:150
 #, c-format
 msgid "libusb_open error :%s\n"
 msgstr ""
 
-#: src/libptouch.c:156
+#: src/libptouch.c:171
+#, c-format
+msgid "%s found on USB bus %d, device %d, serial %s\n"
+msgstr ""
+
+#: src/libptouch.c:200
 #, c-format
 msgid "error while detaching kernel driver: %s\n"
 msgstr ""
 
-#: src/libptouch.c:160
+#: src/libptouch.c:204
 #, c-format
 msgid "interface claim error: %s\n"
 msgstr ""
 
-#: src/libptouch.c:171
+#: src/libptouch.c:218
+#, c-format
+msgid "No P-Touch printer with serial %s found\n"
+msgstr ""
+
+#: src/libptouch.c:220 src/ptouch-print.c:722
 #, c-format
 msgid ""
 "No P-Touch printer found on USB (remember to put switch to position E)\n"
 msgstr ""
 
-#: src/libptouch.c:191
+#: src/libptouch.c:241
 #, c-format
 msgid "debug: called ptouch_send() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:198
+#: src/libptouch.c:248
 #, c-format
 msgid "write error: %s\n"
 msgstr ""
 
-#: src/libptouch.c:202
+#: src/libptouch.c:252
 #, c-format
 msgid "write error: could send only %i of %ld bytes\n"
 msgstr ""
 
-#: src/libptouch.c:252
+#: src/libptouch.c:302
 #, c-format
 msgid "debug: called ptouch_info_cmd() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:294
+#: src/libptouch.c:344
 #, c-format
 msgid "debug: called ptouch_rasterstart() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:325
+#: src/libptouch.c:384
 #, c-format
 msgid "debug: called ptouch_finalize() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:340
+#: src/libptouch.c:399
 #, c-format
 msgid "debug: dumping raw status bytes\n"
 msgstr ""
 
-#: src/libptouch.c:359
+#: src/libptouch.c:418
 #, c-format
 msgid "debug: called ptouch_getstatus() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:369 src/libptouch.c:405
+#: src/libptouch.c:428 src/libptouch.c:459
 #, c-format
 msgid "read error: %s\n"
 msgstr ""
 
-#: src/libptouch.c:374
+#: src/libptouch.c:433
 #, c-format
 msgid "timeout (%i sec) while waiting for status response\n"
 msgstr ""
 
-#: src/libptouch.c:388
+#: src/libptouch.c:442
 #, c-format
 msgid "unknown tape width of %imm, please report this.\n"
 msgstr ""
 
-#: src/libptouch.c:394
+#: src/libptouch.c:448
 #, c-format
 msgid "got only 16 bytes... wondering what they are:\n"
 msgstr ""
 
-#: src/libptouch.c:398
+#: src/libptouch.c:452
 #, c-format
 msgid "read error: got %i instead of 32 bytes\n"
 msgstr ""
 
-#: src/libptouch.c:401
+#: src/libptouch.c:455
 #, c-format
 msgid "strange status:\n"
 msgstr ""
 
-#: src/libptouch.c:403
+#: src/libptouch.c:457
 #, c-format
 msgid "trying to flush junk\n"
 msgstr ""
 
-#: src/libptouch.c:408
+#: src/libptouch.c:462
 #, c-format
 msgid "got another %i bytes. now try again\n"
 msgstr ""
 
-#: src/libptouch.c:415
+#: src/libptouch.c:469
+#, c-format
+msgid "debug: called ptouch_get_dpi() with NULL ptdev\n"
+msgstr ""
+
+#: src/libptouch.c:478
+#, c-format
+msgid "debug: called ptouch_cal_tape_width() with NULL ptdev\n"
+msgstr ""
+
+#: src/libptouch.c:489
+#, c-format
+msgid "printer with %d dpi not supported\n"
+msgstr ""
+
+#: src/libptouch.c:509
+#, c-format
+msgid "debug: called ptouch_get_max_lines() with NULL ptdev\n"
+msgstr ""
+
+#: src/libptouch.c:513
+#, c-format
+msgid "debug: called ptouch_get_max_lines() with invalid fontsize_px\n"
+msgstr ""
+
+#: src/libptouch.c:516
+#, c-format
+msgid "debug: calculated max lines %d \n"
+msgstr ""
+
+#: src/libptouch.c:523
 #, c-format
 msgid "debug: called ptouch_get_tape_width() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:424
+#: src/libptouch.c:532
 #, c-format
 msgid "debug: called ptouch_get_max_width() with NULL ptdev\n"
 msgstr ""
 
-#: src/libptouch.c:436
+#: src/libptouch.c:547
 #, c-format
 msgid "debug: called ptouch_sendraster() with NULL ptdev\n"
 msgstr ""
 
-#: src/ptouch-print.c:153
+#: src/libptouch.c:625
+#, c-format
+msgid "%s\tserial %s\t(USB bus %d, device %d)%s\n"
+msgstr ""
+
+#: src/libptouch.c:629
+msgid " - in P-Lite mode, unsupported"
+msgstr ""
+
+#: src/libptouch.c:630
+msgid " - unsupported"
+msgstr ""
+
+#: src/ptouch-print.c:190
 #, c-format
 msgid "nothing to print\n"
 msgstr ""
 
-#: src/ptouch-print.c:161
+#: src/ptouch-print.c:198
 #, c-format
 msgid "image is too large (%ipx x %ipx)\n"
 msgstr ""
 
-#: src/ptouch-print.c:162
+#: src/ptouch-print.c:199
 #, c-format
 msgid "maximum printing width for this tape is %ipx\n"
 msgstr ""
 
-#: src/ptouch-print.c:165
+#: src/ptouch-print.c:202
 #, c-format
 msgid "image size (%ipx x %ipx)\n"
 msgstr ""
 
-#: src/ptouch-print.c:175
+#: src/ptouch-print.c:218
 #, c-format
 msgid "ptouch_rasterstart() failed\n"
 msgstr ""
 
-#: src/ptouch-print.c:181
+#: src/ptouch-print.c:224
 #, c-format
 msgid "send print information command\n"
 msgstr ""
 
-#: src/ptouch-print.c:187
+#: src/ptouch-print.c:230
 #, c-format
 msgid "send PT-D460BT magic commands\n"
 msgstr ""
 
-#: src/ptouch-print.c:194
+#: src/ptouch-print.c:237
 #, c-format
 msgid "send precut command\n"
 msgstr ""
 
-#: src/ptouch-print.c:203
+#: src/ptouch-print.c:246
 #, c-format
 msgid "send PT-D460BT chain commands\n"
 msgstr ""
 
-#: src/ptouch-print.c:215
+#: src/ptouch-print.c:258
 #, c-format
 msgid "ptouch_sendraster() failed\n"
 msgstr ""
 
-#: src/ptouch-print.c:264
+#: src/ptouch-print.c:307
 #, c-format
 msgid "writing image '%s' failed\n"
 msgstr ""
 
-#: src/ptouch-print.c:286
+#: src/ptouch-print.c:312
 #, c-format
-msgid "debug: o baseline offset - %d\n"
+msgid "printing '%s' requires %.1f mm of tape\n"
 msgstr ""
 
-#: src/ptouch-print.c:287
+#: src/ptouch-print.c:334
+#, c-format
+msgid "debug: z baseline offset - %d\n"
+msgstr ""
+
+#: src/ptouch-print.c:335
 #, c-format
 msgid "debug: text baseline offset - %d\n"
 msgstr ""
 
-#: src/ptouch-print.c:346
+#: src/ptouch-print.c:408
 #, c-format
 msgid "render_text(): %i lines, font = '%s', align = '%c'\n"
 msgstr ""
 
-#: src/ptouch-print.c:349
+#: src/ptouch-print.c:411
 #, c-format
 msgid "warning: font config not available\n"
 msgstr ""
 
-#: src/ptouch-print.c:353
+#: src/ptouch-print.c:415
 #, c-format
 msgid "setting font size=%i\n"
 msgstr ""
 
-#: src/ptouch-print.c:357
+#: src/ptouch-print.c:417
+#, c-format
+msgid "ignoring setting font margin=%i\n"
+msgstr ""
+
+#: src/ptouch-print.c:422
 #, c-format
 msgid "could not estimate needed font size\n"
 msgstr ""
 
-#: src/ptouch-print.c:364
+#: src/ptouch-print.c:429
 #, c-format
 msgid "choosing font size=%i\n"
 msgstr ""
 
-#: src/ptouch-print.c:380 src/ptouch-print.c:414
+#: src/ptouch-print.c:445 src/ptouch-print.c:479
 #, c-format
-msgid "error in gdImageStringFT: %s\n"
+msgid "error in gdImageStringFT_180dpi: %s\n"
 msgstr ""
 
-#: src/ptouch-print.c:571
+#: src/ptouch-print.c:636
 #, c-format
 msgid "Only up to %d lines are supported"
 msgstr ""
 
-#: src/ptouch-print.c:649
+#: src/ptouch-print.c:727
 msgid "No arguments supported"
 msgstr ""
 
-#: src/ptouch-print.c:654
+#: src/ptouch-print.c:732
 msgid "Option --writepng missing"
 msgstr ""
 
-#: src/ptouch-print.c:657
+#: src/ptouch-print.c:735
 msgid "Options --force_tape_width and --info can't be used together"
 msgstr ""
 
-#: src/ptouch-print.c:688
+#: src/ptouch-print.c:766
 #, c-format
 msgid "ptouch_init() failed\n"
 msgstr ""
 
-#: src/ptouch-print.c:691
+#: src/ptouch-print.c:775
 #, c-format
 msgid "ptouch_getstatus() failed\n"
 msgstr ""
 
-#: src/ptouch-print.c:705
+#: src/ptouch-print.c:789
 #, c-format
-msgid "maximum printing width for this printer is %ldpx\n"
+msgid "printer has %d dpi, maximum printing width is %ld px\n"
 msgstr ""
 
-#: src/ptouch-print.c:706
+#: src/ptouch-print.c:790
 #, c-format
 msgid "maximum printing width for this tape is %ldpx\n"
 msgstr ""
 
-#: src/ptouch-print.c:731
+#: src/ptouch-print.c:815
 #, c-format
 msgid "failed to load image file\n"
 msgstr ""
 
-#: src/ptouch-print.c:740
+#: src/ptouch-print.c:824
 #, c-format
 msgid "could not render text\n"
 msgstr ""
 
-#: src/ptouch-print.c:779
+#: src/ptouch-print.c:865
 #, c-format
 msgid "ptouch_finalize(%d) failed\n"
 msgstr ""

ptouch-print.1

@@ -34,9 +34,16 @@ Set the seconds ptouch-print is waiting for finishing a previous ptouch-print co
 Default is 1 second. 0 (zero) means wait forever.
 Useful if ptouch-print is used in a script multiple times, and the device is waiting for the user
 to use the mechanical cutter.
+.TP
+.BR \-\-serial\  \fI<serial>
+Use the printer with this USB serial number, when more than one printer is connected.
+Use \-\-list\-connected to see the serial numbers.
 
 .SS "Font selection options"
 .TP
+.BR \-\-fontmargin\  \fI<size>
+When auto-detecting font size account for a margin above and below the text.
+.TP
 .BR \-\-fontsize\  \fI<size>
 Disable auto-detection of the font size and force the font size to the size
 given as argument. Please note that text will be cut off if you specify a
@@ -87,6 +94,9 @@ Show info about the tape detected (like printing width etc.) and exit.
 .TP
 .BR \-\-list-supported
 List all supported printers
+.TP
+.BR \-\-list-connected
+List all connected printers with their USB serial numbers, for use with \-\-serial
 
 .SH DEFAULTS
 The default font used is 'DejaVuSans'.

src/libptouch.c

@@ -33,69 +33,92 @@
 #define _(s) gettext(s)
 
 /* Print area width in 180 DPI pixels */
+/* The 360dpi print-area values (px360) are Brother's documented values for
+   the PT-P900 series and are NOT simply double the 180dpi ones: the 180dpi
+   figures for wide tapes are clamped by those printers' 128-pin printheads,
+   not the actual printable width. Only 36mm has been verified on hardware;
+   the others come from Brother's raster reference. 21mm has no P900 spec
+   value and keeps the doubled figure. calc_tape_px() clamps the result to
+   the printer's max_px, so printers with a narrower printhead stay safe. */
 struct _pt_tape_info tape_info[]= {
-	{ 4,  24, 0.5},	/* 3.5 mm tape */
+	{ 4,  24,  48, 0.5},	/* 3.5 mm tape */
-	{ 6,  32, 1.0},	/*  6 mm tape */
+	{ 6,  32,  64, 1.0},	/*  6 mm tape */
-	{ 9,  52, 1.0},	/*  9 mm tape */
+	{ 9,  52, 106, 1.0},	/*  9 mm tape */
-	{12,  76, 2.0},	/* 12 mm tape */
+	{12,  76, 150, 2.0},	/* 12 mm tape */
-	{18, 120, 3.0},	/* 18 mm tape */
+	{18, 120, 234, 3.0},	/* 18 mm tape */
-	{21, 124, 3.0},	/* 21 mm tape */
+	{21, 124, 248, 3.0},	/* 21 mm tape (360dpi value unverified) */
-	{24, 128, 3.0},	/* 24 mm tape */
+	{24, 128, 320, 3.0},	/* 24 mm tape */
-	{36, 192, 4.5},	/* 36 mm tape */
+	{36, 192, 454, 4.5},	/* 36 mm tape */
-	{ 0,   0, 0.0}	/* terminating entry */
+	{ 0,   0,   0, 0.0}	/* terminating entry */
 };
 
 struct _pt_dev_info ptdevs[] = {
-	{0x04f9, 0x2001, "PT-9200DX", 384, 360, FLAG_RASTER_PACKBITS|FLAG_HAS_PRECUT},	/* 360dpi, maximum 128px, max tape width 36mm */
+	{0x04f9, 0x2001, "PT-9200DX", 384, 360, FLAG_RASTER_PACKBITS|FLAG_HAS_PRECUT, 0, 0},	/* 360dpi, maximum 128px, max tape width 36mm */
-	{0x04f9, 0x2002, "PT-9200DX", 384, 360, FLAG_RASTER_PACKBITS|FLAG_HAS_PRECUT},	/* reported by Christian Pauls - either 0x2001 is wrong, or this printer exists with two different IDs  */
+	{0x04f9, 0x2002, "PT-9200DX", 384, 360, FLAG_RASTER_PACKBITS|FLAG_HAS_PRECUT, 0, 0},	/* reported by Christian Pauls - either 0x2001 is wrong, or this printer exists with two different IDs  */
-	{0x04f9, 0x2004, "PT-2300", 112, 180, FLAG_RASTER_PACKBITS|FLAG_HAS_PRECUT},	/* 180dpi, 112px printhead */
+	{0x04f9, 0x203c, "PT-9700PC", 384, 360, FLAG_RASTER_PACKBITS|FLAG_HAS_PRECUT|FLAG_P700_INIT|FLAG_USE_INFO_CMD, 0, 0},	/* 360dpi, max tape width 36mm. FLAG_P700_INIT causes printer to send a status response after rasterstart; flushed in ptouch_rasterstart(). */
-	{0x04f9, 0x2007, "PT-2420PC", 128, 180, FLAG_RASTER_PACKBITS},	/* 180dpi, 128px, maximum tape width 24mm, must send TIFF compressed pixel data */
+	{0x04f9, 0x2004, "PT-2300", 112, 180, FLAG_RASTER_PACKBITS|FLAG_HAS_PRECUT, 0, 0},	/* 180dpi, 112px printhead */
-	{0x04f9, 0x2011, "PT-2450PC", 128, 180, FLAG_RASTER_PACKBITS},
+	{0x04f9, 0x2007, "PT-2420PC", 128, 180, FLAG_RASTER_PACKBITS, 0, 0},	/* 180dpi, 128px, maximum tape width 24mm, must send TIFF compressed pixel data */
-	{0x04f9, 0x2019, "PT-1950", 112, 180, FLAG_RASTER_PACKBITS},	/* 180dpi, apparently 112px printhead ?, maximum tape width 18mm - unconfirmed if it works */
+	//{0x04f9, 0x200d, "PT-3600", 384, 360, FLAG_RASTER_PACKBITS, 0, 0},
-	{0x04f9, 0x201f, "PT-2700", 128, 180, FLAG_HAS_PRECUT},
+	{0x04f9, 0x2011, "PT-2450PC", 128, 180, FLAG_RASTER_PACKBITS, 0, 0},
-	{0x04f9, 0x202c, "PT-1230PC", 128, 180, FLAG_NONE},		/* 180dpi, supports tapes up to 12mm - I don't know how much pixels it can print! */
+	{0x04f9, 0x2019, "PT-1950", 112, 180, FLAG_RASTER_PACKBITS, 0, 0},	/* 180dpi, apparently 112px printhead ?, maximum tape width 18mm - unconfirmed if it works */
+	{0x04f9, 0x201f, "PT-2700", 128, 180, FLAG_HAS_PRECUT, 0, 0},
+	{0x04f9, 0x202c, "PT-1230PC", 128, 180, FLAG_NONE, 0, 0},		/* 180dpi, supports tapes up to 12mm - I don't know how much pixels it can print! */
 	/* Notes about the PT-1230PC: While it is true that this printer supports
 	   max 12mm tapes, it apparently expects > 76px data - the first 32px
 	   must be blank. */
-	{0x04f9, 0x202d, "PT-2430PC", 128, 180, FLAG_NONE},		/* 180dpi, maximum 128px */
+	{0x04f9, 0x202d, "PT-2430PC", 128, 180, FLAG_HAS_PRECUT, 0, 0},	/* 180dpi, maximum 128px. Same head width/dpi as PT-2700 (which has FLAG_HAS_PRECUT); confirmed precut works on real hardware. */
-	{0x04f9, 0x2030, "PT-1230PC (PLite Mode)", 128, 180, FLAG_PLITE},
+	{0x04f9, 0x2030, "PT-1230PC (PLite Mode)", 128, 180, FLAG_PLITE, 0, 0},
-	{0x04f9, 0x2031, "PT-2430PC (PLite Mode)", 128, 180, FLAG_PLITE},
+	{0x04f9, 0x2031, "PT-2430PC (PLite Mode)", 128, 180, FLAG_PLITE, 0, 0},
-	{0x04f9, 0x2041, "PT-2730", 128, 180, FLAG_NONE},		/* 180dpi, maximum 128px, max tape width 24mm - reported to work with some quirks */
+	{0x04f9, 0x2041, "PT-2730", 128, 180, FLAG_NONE, 0, 0},		/* 180dpi, maximum 128px, max tape width 24mm - reported to work with some quirks */
 	/* Notes about the PT-2730: was reported to need 48px whitespace
 	   within png-images before content is actually printed - can not check this */
-	{0x04f9, 0x205e, "PT-H500", 128, 180, FLAG_RASTER_PACKBITS|FLAG_HAS_PRECUT},
+	{0x04f9, 0x205e, "PT-H500", 128, 180, FLAG_RASTER_PACKBITS|FLAG_HAS_PRECUT, 0, 0},
 	/* Note about the PT-H500: was reported by Eike with the remark that
 	   it might need some trailing padding */
-	{0x04f9, 0x205f, "PT-E500", 128, 180, FLAG_RASTER_PACKBITS},
+	{0x04f9, 0x205f, "PT-E500", 128, 180, FLAG_RASTER_PACKBITS, 0, 0},
 	/* Note about the PT-E500: was reported by Jesse Becker with the
 	   remark that it also needs some padding (white pixels) */
-	{0x04f9, 0x2060, "PT-E550W", 128, 180, FLAG_UNSUP_RASTER},
+	{0x04f9, 0x2060, "PT-E550W", 128, 180, FLAG_UNSUP_RASTER, 0, 0},
 	/* Note about the PT-E550W: was reported by Tim Biermann but does not
 	   work yet (only prints empty tape with FLAG_RASTER_PACKBITS|FLAG_HAS_PRECUT) */
-	{0x04f9, 0x2061, "PT-P700", 128, 180, FLAG_RASTER_PACKBITS|FLAG_P700_INIT|FLAG_HAS_PRECUT},
+	{0x04f9, 0x2061, "PT-P700", 128, 180, FLAG_RASTER_PACKBITS|FLAG_P700_INIT|FLAG_HAS_PRECUT, 0, 0},
-	{0x04f9, 0x2062, "PT-P750W", 128, 180, FLAG_RASTER_PACKBITS|FLAG_P700_INIT},
+	{0x04f9, 0x2062, "PT-P750W", 128, 180, FLAG_RASTER_PACKBITS|FLAG_P700_INIT, 0, 0},
-	{0x04f9, 0x2064, "PT-P700 (PLite Mode)", 128, 180, FLAG_PLITE},
+	{0x04f9, 0x2064, "PT-P700 (PLite Mode)", 128, 180, FLAG_PLITE, 0, 0},
-	{0x04f9, 0x2065, "PT-P750W (PLite Mode)", 128, 180, FLAG_PLITE},
+	{0x04f9, 0x2065, "PT-P750W (PLite Mode)", 128, 180, FLAG_PLITE, 0, 0},
-	{0x04f9, 0x20df, "PT-D410", 128, 180, FLAG_USE_INFO_CMD|FLAG_HAS_PRECUT|FLAG_D460BT_MAGIC},
+	{0x04f9, 0x2073, "PT-D450", 128, 180, FLAG_USE_INFO_CMD, 0, 0},
-	{0x04f9, 0x2073, "PT-D450", 128, 180, FLAG_USE_INFO_CMD},
 	/* Notes about the PT-D450: I'm unsure if print width really is 128px */
-	{0x04f9, 0x20e0, "PT-D460BT", 128, 180, FLAG_P700_INIT|FLAG_USE_INFO_CMD|FLAG_HAS_PRECUT|FLAG_D460BT_MAGIC},
+	{0x04f9, 0x2074, "PT-D600", 128, 180, FLAG_RASTER_PACKBITS, 0, 0},
-	{0x04f9, 0x2074, "PT-D600", 128, 180, FLAG_RASTER_PACKBITS},
 	/* PT-D600 was reported to work, but with some quirks (premature
 	   cutting of tape, printing maximum of 73mm length) */
-	{0x04f9, 0x20e1, "PT-D610BT", 128, 180, FLAG_P700_INIT|FLAG_USE_INFO_CMD|FLAG_HAS_PRECUT|FLAG_D460BT_MAGIC},
+	{0x04f9, 0x2085, "PT-P900Wc", 560, 360, FLAG_RASTER_PACKBITS|FLAG_P700_INIT|FLAG_USE_INFO_CMD|FLAG_HAS_PRECUT, -8, 0},
-	//{0x04f9, 0x200d, "PT-3600", 384, 360, FLAG_RASTER_PACKBITS},
+	/* PT-P900Wc: 360dpi, 560px printhead (70 bytes/raster line). Verified
-	{0x04f9, 0x20af, "PT-P710BT", 128, 180, FLAG_RASTER_PACKBITS|FLAG_HAS_PRECUT},
+	   printing on 36mm laminated tape. Narrower tape widths use Brother's
+	   documented 360dpi print areas (see tape_info) but are untested.
+	   pin_offset = -8: the print area is centred at pin 272, not the head
+	   centre (pin 280) - a constant offset across all tape widths. See the
+	   Brother "Software Developer's Manual - Raster Command Reference,
+	   PT-P900/P900W/P950NW", section 2.3.5 "Raster line". */
+	{0x04f9, 0x20af, "PT-P710BT", 128, 180, FLAG_RASTER_PACKBITS|FLAG_HAS_PRECUT, 0, 0},
+	{0x04f9, 0x20df, "PT-D410", 128, 180, FLAG_USE_INFO_CMD|FLAG_HAS_PRECUT|FLAG_D460BT_MAGIC, 0, 0},
+	{0x04f9, 0x20e0, "PT-D460BT", 128, 180, FLAG_P700_INIT|FLAG_USE_INFO_CMD|FLAG_HAS_PRECUT|FLAG_D460BT_MAGIC, 0, 0},
+	{0x04f9, 0x20e1, "PT-D610BT", 128, 180, FLAG_P700_INIT|FLAG_USE_INFO_CMD|FLAG_HAS_PRECUT|FLAG_D460BT_MAGIC, 0, 0},
 	/* added by Christian, PT-E310BT (aka PT-E310BTVP) requires these flags, otherwise not returning from libusb_bulk_transfer-call */
 	/* printhead 128px, 180 dpi resolution */
 	/* 3,5/6/9/12/18 mm TZe Tapes, 12mm and 18mm tested */
 	/* 5,2/9/11,2 mm HSe heat shrink tubes not tested, probably requiring extension of struct _pt_tape_info */
-	{0x04f9, 0x2201, "PT-E310BT", 128, 180, FLAG_P700_INIT|FLAG_USE_INFO_CMD|FLAG_D460BT_MAGIC},
+	{0x04f9, 0x2201, "PT-E310BT", 128, 180, FLAG_P700_INIT|FLAG_USE_INFO_CMD|FLAG_D460BT_MAGIC, 0, 0},
-	{0x04f9, 0x2203, "PT-E560BT", 128, 180, FLAG_P700_INIT|FLAG_USE_INFO_CMD|FLAG_D460BT_MAGIC},
+	{0x04f9, 0x2203, "PT-E560BT", 128, 180, FLAG_P700_INIT|FLAG_USE_INFO_CMD|FLAG_D460BT_MAGIC, 0, 10},
-	{0,0,"",0,0,0}
+	{0,0,"",0,0,0,0,0}
 };
 
 int ptouch_open(ptouch_dev *ptdev)
+{
+	return ptouch_open_serial(ptdev, NULL);
+}
+
+/* Like ptouch_open(), but when serial is not NULL only a printer whose
+   USB serial number matches it is used. */
+int ptouch_open_serial(ptouch_dev *ptdev, const char *serial)
 {
 	libusb_device **devs;
 	libusb_device *dev;
@@ -132,22 +155,43 @@ int ptouch_open(ptouch_dev *ptdev)
 		}
 		for (int k=0; ptdevs[k].vid > 0; ++k) {
 			if ((desc.idVendor == ptdevs[k].vid) && (desc.idProduct == ptdevs[k].pid) && (ptdevs[k].flags >= 0)) {
-				fprintf(stderr, _("%s found on USB bus %d, device %d\n"),
+				unsigned char buf[64] = {0};
+				if ((r=libusb_open(dev, &handle)) != 0) {
+					fprintf(stderr, _("libusb_open error :%s\n"), libusb_error_name(r));
+					if (serial) {
+						/* can't read its serial, so it can't be the one we want */
+						break;
+					}
+					libusb_free_device_list(devs, 1);
+					return -1;
+				}
+				if (desc.iSerialNumber) {
+					libusb_get_string_descriptor_ascii(handle, desc.iSerialNumber, buf, sizeof(buf));
+				}
+				fprintf(stderr, _("%s found on USB bus %d, device %d, serial %s\n"),
 					ptdevs[k].name,
 					libusb_get_bus_number(dev),
-					libusb_get_device_address(dev));
+					libusb_get_device_address(dev),
+					buf[0] ? (char *)buf : "-");
+				/* check the serial before the P-Lite/unsupported checks, so
+				   a different printer in the wrong mode doesn't end the search */
+				if (serial && (strcmp((char *)buf, serial) != 0)) {
+					libusb_close(handle);
+					handle = NULL;
+					break;	/* next device */
+				}
 				if (ptdevs[k].flags & FLAG_PLITE) {
 					printf("Printer is in P-Lite Mode, which is unsupported\n\n");
 					printf("Turn off P-Lite mode by changing switch from position EL to position E\n");
 					printf("or by pressing the PLite button for ~ 2 seconds (or consult the manual)\n");
+					libusb_close(handle);
+					libusb_free_device_list(devs, 1);
 					return -1;
 				}
 				if (ptdevs[k].flags & FLAG_UNSUP_RASTER) {
 					printf("Unfortunately, that printer currently is unsupported (it has a different raster data transfer)\n");
-					return -1;
+					libusb_close(handle);
-				}
+					libusb_free_device_list(devs, 1);
-				if ((r=libusb_open(dev, &handle)) != 0) {
-					fprintf(stderr, _("libusb_open error :%s\n"), libusb_error_name(r));
 					return -1;
 				}
 				libusb_free_device_list(devs, 1);
@@ -164,11 +208,17 @@ int ptouch_open(ptouch_dev *ptdev)
 				(*ptdev)->devinfo->dpi=ptdevs[k].dpi;
 				(*ptdev)->devinfo->max_px=ptdevs[k].max_px;
 				(*ptdev)->devinfo->flags=ptdevs[k].flags;
+				(*ptdev)->devinfo->pin_offset=ptdevs[k].pin_offset;
+				(*ptdev)->devinfo->min_timeout=ptdevs[k].min_timeout;
 				return 0;
 			}
 		}
 	}
-	fprintf(stderr, _("No P-Touch printer found on USB (remember to put switch to position E)\n"));
+	if (serial) {
+		fprintf(stderr, _("No P-Touch printer with serial %s found\n"), serial);
+	} else {
+		fprintf(stderr, _("No P-Touch printer found on USB (remember to put switch to position E)\n"));
+	}
 	libusb_free_device_list(devs, 1);
 	return -1;
 }
@@ -299,7 +349,16 @@ int ptouch_rasterstart(ptouch_dev ptdev)
 	/* 1B 69 61 01 = switch mode (0=esc/p, 1=raster mode) */
 	char cmd2[] = "\x1b\x69\x61\x01";
 	if (ptdev->devinfo->flags & FLAG_P700_INIT) {
-		return ptouch_send(ptdev, (uint8_t *)cmd2, strlen(cmd2));
+		int r = ptouch_send(ptdev, (uint8_t *)cmd2, strlen(cmd2));
+		if (r != 0) {
+			return r;
+		}
+		/* Printer sends a status response after entering raster mode;
+		   flush it so subsequent raster writes don't block. */
+		uint8_t buf[32];
+		int tx = 0;
+		libusb_bulk_transfer(ptdev->h, 0x81, buf, sizeof(buf), &tx, 1000);
+		return 0;
 	} /* else */
 	return ptouch_send(ptdev, (uint8_t *)cmd, strlen(cmd));
 }
@@ -352,7 +411,7 @@ int ptouch_getstatus(ptouch_dev ptdev, int timeout)
 {
 	char cmd[]="\x1biS";	/* 1B 69 53 = ESC i S = Status info request */
 	uint8_t buf[32] = {};
-	int i, r, tx=0, tries=0, maxtries=timeout*10;
+	int r, tx=0, tries=0, maxtries=timeout*10;
 	struct timespec w;
 
 	if (!ptdev) {
@@ -378,12 +437,7 @@ int ptouch_getstatus(ptouch_dev ptdev, int timeout)
 	if (tx == 32) {
 		if (buf[0]==0x80 && buf[1]==0x20) {
 			memcpy(ptdev->status, buf, 32);
-			ptdev->tape_width_px=0;
+			ptdev->tape_width_px = ptouch_calc_tape_px(ptdev, buf[10]);
-			for (i=0; tape_info[i].mm > 0; ++i) {
-				if (tape_info[i].mm == buf[10]) {
-					ptdev->tape_width_px=tape_info[i].px;
-				}
-			}
 			if (ptdev->tape_width_px == 0) {
 				fprintf(stderr, _("unknown tape width of %imm, please report this.\n"), buf[10]);
 			}
@@ -409,6 +463,60 @@ int ptouch_getstatus(ptouch_dev ptdev, int timeout)
 	return -1;
 }
 
+int ptouch_get_dpi(ptouch_dev ptdev)
+{
+	if (!ptdev) {
+		fprintf(stderr, _("debug: called ptouch_get_dpi() with NULL ptdev\n"));
+		return 0;
+	}
+	return ptdev->devinfo->dpi;
+}
+
+int ptouch_calc_tape_px(ptouch_dev ptdev, const uint8_t tape_width_mm)
+{
+	if (!ptdev) {
+		fprintf(stderr, _("debug: called ptouch_cal_tape_width() with NULL ptdev\n"));
+		return 0;
+	}
+	int tape_width_px = 0;
+	for (int i=0; tape_info[i].mm > 0; ++i) {
+		if (tape_info[i].mm == tape_width_mm) {
+			if (ptdev->devinfo->dpi == 180) {
+				tape_width_px = tape_info[i].px;
+			} else if (ptdev->devinfo->dpi == 360) {
+				tape_width_px = tape_info[i].px360;
+			} else {
+				fprintf(stderr, _("printer with %d dpi not supported\n"), ptdev->devinfo->dpi);
+			}
+		}
+	}
+	/* Never print wider than the physical printhead. This also keeps 360dpi
+	   printers with a narrower head (e.g. PT-9200DX, 384px) safe when the
+	   tape's printable area exceeds what they can drive. */
+	if (tape_width_px > ptdev->devinfo->max_px) {
+		tape_width_px = ptdev->devinfo->max_px;
+	}
+	return tape_width_px;
+}
+
+/* TODO: The actual number of maximum lines should be calculated according to
+   printer resolution, tapewidth and fontsize */
+/* printer resolution is planned to be taken into account when calculating
+   tape_width in px */
+int ptouch_get_max_lines(ptouch_dev ptdev, int fontsize_px)
+{
+	if (!ptdev) {
+		fprintf(stderr, _("debug: called ptouch_get_max_lines() with NULL ptdev\n"));
+		return 0;
+	}
+	if (fontsize_px <= 0) {
+		fprintf(stderr, _("debug: called ptouch_get_max_lines() with invalid fontsize_px\n"));
+		return 0;
+	}
+	fprintf(stderr, _("debug: calculated max lines %d \n"), ptdev->tape_width_px / fontsize_px);
+	return 4;
+}
+
 size_t ptouch_get_tape_width(ptouch_dev ptdev)
 {
 	if (!ptdev) {
@@ -429,7 +537,10 @@ size_t ptouch_get_max_width(ptouch_dev ptdev)
 
 int ptouch_sendraster(ptouch_dev ptdev, uint8_t *data, size_t len)
 {
-	uint8_t buf[64];
+	/* Must hold a full raster line (max_px/8 bytes) plus up to 4 header
+	   bytes. ptouch_send() caps a packet at 128 bytes, so this is the
+	   largest a packet can ever be. */
+	uint8_t buf[128];
 	int rc;
 
 	if (!ptdev) {
@@ -476,6 +587,57 @@ void ptouch_list_supported()
 	return;
 }
 
+/* Print every connected P-Touch printer with its USB serial number, which
+   can then be passed to ptouch_open_serial(). Returns the number of
+   printers found, or -1 on error. */
+int ptouch_list_connected()
+{
+	libusb_device **devs;
+	libusb_device *dev;
+	libusb_device_handle *handle;
+	struct libusb_device_descriptor desc;
+	int r, i=0, found=0;
+
+	if ((libusb_init(NULL)) < 0) {
+		fprintf(stderr, _("libusb_init() failed\n"));
+		return -1;
+	}
+	if (libusb_get_device_list(NULL, &devs) < 0) {
+		libusb_exit(NULL);
+		return -1;
+	}
+	while ((dev=devs[i++]) != NULL) {
+		if (libusb_get_device_descriptor(dev, &desc) < 0) {
+			continue;
+		}
+		for (int k=0; ptdevs[k].vid > 0; ++k) {
+			if ((desc.idVendor == ptdevs[k].vid) && (desc.idProduct == ptdevs[k].pid) && (ptdevs[k].flags >= 0)) {
+				unsigned char buf[64] = {0};
+				const char *serial = "-";
+				if ((r=libusb_open(dev, &handle)) != 0) {
+					serial = libusb_error_name(r);
+				} else {
+					if (desc.iSerialNumber && (libusb_get_string_descriptor_ascii(handle, desc.iSerialNumber, buf, sizeof(buf)) > 0)) {
+						serial = (char *)buf;
+					}
+					libusb_close(handle);
+				}
+				printf(_("%s\tserial %s\t(USB bus %d, device %d)%s\n"),
+					ptdevs[k].name, serial,
+					libusb_get_bus_number(dev),
+					libusb_get_device_address(dev),
+					(ptdevs[k].flags & FLAG_PLITE) ? _(" - in P-Lite mode, unsupported") :
+					(ptdevs[k].flags & FLAG_UNSUP_RASTER) ? _(" - unsupported") : "");
+				++found;
+				break;
+			}
+		}
+	}
+	libusb_free_device_list(devs, 1);
+	libusb_exit(NULL);
+	return found;
+}
+
 const char* pt_mediatype(const uint8_t media_type)
 {
 	switch (media_type) {

src/ptouch-print.c

@@ -35,7 +35,17 @@
 
 #define _(s) gettext(s)
 
-#define MAX_LINES 4	/* maybe this should depend on tape size */
+#ifdef NEED_STRCHRNUL
+/* GNU extension. argp-standalone references it, so platforms that need
+   argp-standalone need this too. Selected by cmake/Findargp.cmake. */
+char *strchrnul(const char *s, int c)
+{
+	const char *p = strchr(s, c);
+	return (char *)(p ? p : s + strlen(s));
+}
+#endif
+
+#define MAX_LINES 4	/* this should be calculated depending on tape size */
 
 #define P_NAME "ptouch-print"
 
@@ -50,11 +60,14 @@ struct arguments {
 	bool info;
 	char *font_file;
 	int font_size;
+	int font_margin;
 	int forced_tape_width;
 	char *save_png;
 	int verbose;
 	int timeout;
+	char *serial;
 };
+
 typedef enum { JOB_CUTMARK, JOB_IMAGE, JOB_PAD, JOB_TEXT, JOB_UNDEFINED } job_type_t;
 
 typedef struct job {
@@ -88,11 +101,16 @@ static struct argp_option options[] = {
 	{ 0, 0, 0, 0, "options:", 1},
 	{ "debug", 1, 0, 0, "Enable debug output", 1},
 	{ "font", 2, "<file>", 0, "Use font <file> or <name>", 1},
-	{ "fontsize", 3, "<size>", 0, "Manually set font size", 1},
+	{ "font-size", 3, "<size>", 0, "Manually set font size, or ...", 1},
-	{ "writepng", 4, "<file>", 0, "Instead of printing, write output to png <file>", 1},
+	{ "fontsize", 3, "<size>", OPTION_ALIAS, "alias for font-size", 1},
-	{ "force-tape-width", 5, "<px>", 0, "Set tape width in pixels, use together with --writepng without a printer connected", 1},
+	{ "font-margin", 4, "<size>", 0, "Manually set font top/bottom margin (in px)", 1},
-	{ "copies", 6, "<number>", 0, "Sets the number of identical prints", 1},
+	{ "fontmargin", 4, "<size>", OPTION_ALIAS, "alias for font-margin", 1},
-	{ "timeout", 7, "<seconds>", 0, "Set timeout waiting for finishing previous job. Default:1, 0 means infinity", 1},
+	{ "write-png", 'w', "<file>", 0, "Instead of printing, write output to png <file>", 1},
+	{ "writepng", 'w', "<file>", OPTION_ALIAS, "alias for write-png", 1},
+	{ "force-tape-width", 6, "<px>", 0, "Set tape width in pixels, use together with --writepng without a printer connected", 1},
+	{ "copies", 7, "<number>", 0, "Sets the number of identical prints", 1},
+	{ "timeout", 8, "<seconds>", 0, "Set timeout waiting for finishing previous job. Default:1, or a per-printer minimum where one is known. 0 means infinity", 1},
+	{ "serial", 12, "<serial>", 0, "Use the printer with this USB serial number", 1 },
 
 	{ 0, 0, 0, 0, "print commands:", 2},
 	{ "image", 'i', "<file>", 0, "Print the given image which must be a 2 color (black/white) png", 2},
@@ -107,6 +125,7 @@ static struct argp_option options[] = {
 	{ 0, 0, 0, 0, "other commands:", 3},
 	{ "info", 20, 0, 0, "Show info about detected tape", 3},
 	{ "list-supported", 21, 0, 0, "Show printers supported by this version", 3},
+	{ "list-connected", 22, 0, 0, "Show connected printers and their USB serial numbers (for --serial)", 3},
 	{ 0 }
 };
 
@@ -125,12 +144,30 @@ struct arguments arguments = {
 	.forced_tape_width = 0,
 	.save_png = NULL,
 	.verbose = 0,
-	.timeout = 1
+	.timeout = -1,		/* -1 = not given; 0 is already "infinity" */
+	.serial = NULL
 };
 
 job_t *jobs = NULL;
 job_t *last_added_job = NULL;
 
+
+/* --------------------------------------------------------------------
+   -------------------------------------------------------------------- */
+
+char * gdImageStringFT_180dpi(gdImagePtr im, int *brect, int fg, char *fontlist, double ptsize, double angle, int x, int y, char *string)
+{
+	gdFTStringExtra extra;
+	memset(&extra, 0, sizeof(gdFTStringExtra));
+
+	extra.flags = gdFTEX_RESOLUTION;
+	extra.hdpi = 180;
+	extra.vdpi = 180;
+
+	return gdImageStringFTEx(im, brect, fg, fontlist, ptsize, angle, x, y, string, &extra);
+}
+
+
 /* --------------------------------------------------------------------
    -------------------------------------------------------------------- */
 
@@ -163,7 +200,13 @@ int print_img(ptouch_dev ptdev, gdImage *im, int chain, int precut)
 		return -1;
 	}
 	printf(_("image size (%ipx x %ipx)\n"), gdImageSX(im), gdImageSY(im));
-	int offset = ((int)max_pixels / 2) - (gdImageSY(im)/2);	/* always print centered */
+	int offset = ((int)max_pixels / 2) - (gdImageSY(im)/2);	/* center within the printhead */
+	/* Some models do not center the print area on the printhead. pin_offset
+	   is a fixed per-device shift (in pins/px, constant across tape widths)
+	   that corrects for this; it is 0 where centering is already correct.
+	   See the Brother "Software Developer's Manual - Raster Command
+	   Reference, PT-P900/P900W/P950NW", section 2.3.5 "Raster line". */
+	offset += ptdev->devinfo->pin_offset;
 	printf("max_pixels=%ld, offset=%d\n", max_pixels, offset);
 	if ((ptdev->devinfo->flags & FLAG_RASTER_PACKBITS) == FLAG_RASTER_PACKBITS) {
 		if (arguments.debug) {
@@ -266,6 +309,7 @@ int write_png(gdImage *im, const char *file)
 	}
 	gdImagePng(im, f);
 	fclose(f);
+	printf(_("printing '%s' requires %.1f mm of tape\n"), file, (float)gdImageSX(im) / gdImageResolutionX(im) * 25.4);
 	return 0;
 }
 
@@ -277,16 +321,20 @@ int get_baselineoffset(char *text, char *font, int fsz)
 {
 	int brect[8];
 
-	/* NOTE: This assumes that 'o' is always on the baseline */
+	/* NOTE: This assumes that 'z' is on the baseline for the selected font.
-	gdImageStringFT(NULL, &brect[0], -1, font, fsz, 0.0, 0, 0, "o");
+	   'z' was choosen instead of 'o' because letters withstraight baseline
-	int o_offset = brect[1];
+	   are the better choice for the majority of fonts here.
-	gdImageStringFT(NULL, &brect[0], -1, font, fsz, 0.0, 0, 0, text);
+	   If this makes problems with non-latin fonts with lots of vertically
+	   protruding serifs or decorations, change 'z' to 'o' */
+	gdImageStringFT_180dpi(NULL, &brect[0], -1, font, fsz, 0.0, 0, 0, "z");
+	int z_offset = brect[1];
+	gdImageStringFT_180dpi(NULL, &brect[0], -1, font, fsz, 0.0, 0, 0, text);
 	int text_offset = brect[1];
 	if (arguments.debug) {
-		printf(_("debug: o baseline offset - %d\n"), o_offset);
+		printf(_("debug: z baseline offset - %d\n"), z_offset);
 		printf(_("debug: text baseline offset - %d\n"), text_offset);
 	}
-	return text_offset-o_offset;
+	return text_offset-z_offset;
 }
 
 /* --------------------------------------------------------------------
@@ -296,11 +344,22 @@ int get_baselineoffset(char *text, char *font, int fsz)
    -------------------------------------------------------------------- */
 int find_fontsize(int want_px, char *font, char *text)
 {
+	// stabilize font size determination by always accounting for common ascenders and descenders
+	const char *common_chars = "!\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnoprqstuvwxyz{|}~";
+	char *combined_text = (char *)malloc(strlen(text) + strlen(common_chars) + 1);
+	if (!combined_text) {
+		fprintf(stderr, "Memory allocation failed\n");
+		return -1;
+	}
+
+	strcpy(combined_text, text);
+	strcat(combined_text, common_chars);
+
 	int save = 0;
 	int brect[8];
 
 	for (int i=4; ; ++i) {
-		if (gdImageStringFT(NULL, &brect[0], -1, font, i, 0.0, 0, 0, text) != NULL) {
+		if (gdImageStringFT_180dpi(NULL, &brect[0], -1, font, i, 0.0, 0, 0, combined_text) != NULL) {
 			break;
 		}
 		if (brect[1]-brect[5] <= want_px) {
@@ -309,6 +368,9 @@ int find_fontsize(int want_px, char *font, char *text)
 			break;
 		}
 	}
+
+	free(combined_text);
+
 	if (save == 0) {
 		return -1;
 	}
@@ -319,7 +381,7 @@ int needed_width(char *text, char *font, int fsz)
 {
 	int brect[8];
 
-	if (gdImageStringFT(NULL, &brect[0], -1, font, fsz, 0.0, 0, 0, text) != NULL) {
+	if (gdImageStringFT_180dpi(NULL, &brect[0], -1, font, fsz, 0.0, 0, 0, text) != NULL) {
 		return -1;
 	}
 	return brect[2]-brect[0];
@@ -329,7 +391,7 @@ int offset_x(char *text, char *font, int fsz)
 {
 	int brect[8];
 
-	if (gdImageStringFT(NULL, &brect[0], -1, font, fsz, 0.0, 0, 0, text) != NULL) {
+	if (gdImageStringFT_180dpi(NULL, &brect[0], -1, font, fsz, 0.0, 0, 0, text) != NULL) {
 		return -1;
 	}
 	return -brect[0];
@@ -351,9 +413,12 @@ gdImage *render_text(char *font, char *line[], int lines, int print_width)
 	if (arguments.font_size > 0) {
 		fsz = arguments.font_size;
 		printf(_("setting font size=%i\n"), fsz);
+		if (arguments.font_margin > 0) {
+			printf(_("ignoring setting font margin=%i\n"), arguments.font_margin);
+		}
 	} else {
 		for (i = 0; i < lines; ++i) {
-			if ((tmp = find_fontsize(print_width/lines, font, line[i])) < 0) {
+			if ((tmp = find_fontsize((print_width-2*arguments.font_margin)/lines, font, line[i])) < 0) {
 				printf(_("could not estimate needed font size\n"));
 				return NULL;
 			}
@@ -372,12 +437,12 @@ gdImage *render_text(char *font, char *line[], int lines, int print_width)
 	im = gdImageCreatePalette(x, print_width);
 	gdImageColorAllocate(im, 255, 255, 255);
 	black = gdImageColorAllocate(im, 0, 0, 0);
-	/* gdImageStringFT(im,brect,fg,fontlist,size,angle,x,y,string) */
+	/* gdImageStringFT_180dpi(im,brect,fg,fontlist,size,angle,x,y,string) */
 	/* find max needed line height for ALL lines */
 	int max_height=0;
 	for (i = 0; i < lines; ++i) {
-		if ((p = gdImageStringFT(NULL, &brect[0], -black, font, fsz, 0.0, 0, 0, line[i])) != NULL) {
+		if ((p = gdImageStringFT_180dpi(NULL, &brect[0], -black, font, fsz, 0.0, 0, 0, line[i])) != NULL) {
-			printf(_("error in gdImageStringFT: %s\n"), p);
+			printf(_("error in gdImageStringFT_180dpi: %s\n"), p);
 		}
 		//int ofs = get_baselineoffset(line[i], font_file, fsz);
 		int lineheight = brect[1]-brect[5];
@@ -410,8 +475,8 @@ gdImage *render_text(char *font, char *line[], int lines, int print_width)
 		} else if (arguments.align == ALIGN_RIGHT) {
 			align_ofs = x - needed_width(line[i], arguments.font_file, fsz);
 		}
-		if ((p = gdImageStringFT(im, &brect[0], -black, font, fsz, 0.0, off_x + align_ofs, pos, line[i])) != NULL) {
+		if ((p = gdImageStringFT_180dpi(im, &brect[0], -black, font, fsz, 0.0, off_x + align_ofs, pos, line[i])) != NULL) {
-			printf(_("error in gdImageStringFT: %s\n"), p);
+			printf(_("error in gdImageStringFT_180dpi: %s\n"), p);
 		}
 	}
 	return im;
@@ -593,16 +658,19 @@ static error_t parse_opt(int key, char *arg, struct argp_state *state)
 		case 3: // fontsize
 			arguments->font_size = strtol(arg, NULL, 10);
 			break;
-		case 4: // writepng
+		case 4: // fontmargin
+			arguments->font_margin = strtol(arg, NULL, 10);
+			break;
+		case 'w': // write-png
 			arguments->save_png = arg;
 			break;
-		case 5: // force-tape-width
+		case 6: // force-tape-width
 			arguments->forced_tape_width = strtol(arg, NULL, 10);
 			break;
-		case 6: // copies
+		case 7: // copies
 			arguments->copies = strtol(arg, NULL, 10);
 			break;
-		case 7: // timeout
+		case 8: // timeout
 			arguments->timeout = strtol(arg, NULL, 10);
 			break;
 		case 'i': // image
@@ -624,6 +692,9 @@ static error_t parse_opt(int key, char *arg, struct argp_state *state)
 		case 11: // precut
 			arguments->precut = true;
 			break;
+		case 12: // serial
+			arguments->serial = arg;
+			break;
 		case 'a': // align
 			if ((strcmp(arg, "c") == 0) || (strcmp(arg, "center") == 0)) {
 				arguments->align = ALIGN_CENTER;
@@ -645,6 +716,13 @@ static error_t parse_opt(int key, char *arg, struct argp_state *state)
 		case 21: // list-supported
 			ptouch_list_supported();
 			exit(0);
+		case 22: { // list-connected
+			int n = ptouch_list_connected();
+			if (n == 0) {
+				fprintf(stderr, _("No P-Touch printer found on USB (remember to put switch to position E)\n"));
+			}
+			exit(n > 0 ? 0 : 5);
+		}
 		case ARGP_KEY_ARG:
 			argp_failure(state, 1, E2BIG, _("No arguments supported"));
 			break;
@@ -681,12 +759,18 @@ int main(int argc, char *argv[])
 	argp_parse(&argp, argc, argv, 0, 0, &arguments);
 
 	if (!arguments.forced_tape_width) {
-		if ((ptouch_open(&ptdev)) < 0) {
+		if ((ptouch_open_serial(&ptdev, arguments.serial)) < 0) {
 			return 5;
 		}
 		if (ptouch_init(ptdev) != 0) {
 			printf(_("ptouch_init() failed\n"));
 		}
+		/* Resolve the timeout only now, because it can depend on which
+		   printer answered. An explicit --timeout always wins. */
+		if (arguments.timeout < 0) {
+			arguments.timeout = ptdev->devinfo->min_timeout > 0
+				? ptdev->devinfo->min_timeout : 1;
+		}
 		if (ptouch_getstatus(ptdev, arguments.timeout) != 0) {
 			printf(_("ptouch_getstatus() failed\n"));
 			return 1;
@@ -702,7 +786,7 @@ int main(int argc, char *argv[])
 	}
 
 	if (arguments.info) {
-		printf(_("maximum printing width for this printer is %ldpx\n"), ptouch_get_max_width(ptdev));
+		printf(_("printer has %d dpi, maximum printing width is %ld px\n"), ptouch_get_dpi(ptdev), ptouch_get_max_width(ptdev));
 		printf(_("maximum printing width for this tape is %ldpx\n"), ptouch_get_tape_width(ptdev));
 		printf("media type = 0x%02x (%s)\n", ptdev->status->media_type, pt_mediatype(ptdev->status->media_type));
 		printf("media width = %d mm\n", ptdev->status->media_width);
@@ -771,6 +855,8 @@ int main(int argc, char *argv[])
 
 	if (out) {
 		if (arguments.save_png) {
+			int dpi = ptouch_get_dpi(ptdev);
+			gdImageSetResolution(out, dpi, dpi);
 			write_png(out, arguments.save_png);
 		} else {
 			for (int i = 0; i < arguments.copies; ++i) {

udev/20-usb-ptouch-permissions.rules

@@ -1,4 +1,6 @@
 # Enable non-root access for known ptouch printers
+SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2001", MODE="0660", TAG+="uaccess"
+SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2002", MODE="0660", TAG+="uaccess"
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2004", MODE="0660", TAG+="uaccess"
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2007", MODE="0660", TAG+="uaccess"
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2011", MODE="0660", TAG+="uaccess"
@@ -6,15 +8,22 @@ SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2019", MODE=
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "201f", MODE="0660", TAG+="uaccess"
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "202c", MODE="0660", TAG+="uaccess"
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "202d", MODE="0660", TAG+="uaccess"
+SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2030", MODE="0660", TAG+="uaccess"
+SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2031", MODE="0660", TAG+="uaccess"
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2041", MODE="0660", TAG+="uaccess"
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "205e", MODE="0660", TAG+="uaccess"
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "205f", MODE="0660", TAG+="uaccess"
+SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2060", MODE="0660", TAG+="uaccess"
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2061", MODE="0660", TAG+="uaccess"
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2062", MODE="0660", TAG+="uaccess"
+SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2064", MODE="0660", TAG+="uaccess"
+SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2065", MODE="0660", TAG+="uaccess"
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2073", MODE="0660", TAG+="uaccess"
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2074", MODE="0660", TAG+="uaccess"
+SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2085", MODE="0660", TAG+="uaccess"
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "20af", MODE="0660", TAG+="uaccess"
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "20df", MODE="0660", TAG+="uaccess"
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "20e0", MODE="0660", TAG+="uaccess"
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "20e1", MODE="0660", TAG+="uaccess"
 SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2201", MODE="0660", TAG+="uaccess"
+SUBSYSTEM == "usb", ATTRS{idVendor} == "04f9", ATTRS{idProduct} == "2203", MODE="0660", TAG+="uaccess"