xgettext - extract gettext call strings from C programs
xgettext [-ns] [-a [-x exclude-file]] [-c comment-tag] [-d default-domain] [-j] [-m prefix] [-M suffix] [-p pathname] -| filename...
The xgettext utility is used to automate the creation of portable message files (.po). A .po file contains copies of “C” strings that are found in ANSI C source code in filename or the standard input if ‘−’ is specified on the command line. The .po file can be used as input to the msgfmt(1) utility, which produces a binary form of the message file that can be used by application during runtime.
xgettext writes msgid strings from gettext(3C) calls in filename to the default output file messages.po. The default output file name can be changed by –d option. msgid strings in dgettext() calls are written to the output file domainname.po where domainname is the first parameter to the dgettext() call.
By default, xgettext creates a .po file in the current working directory, and each entry is in the same order that the strings are extracted from filenames. When the –p option is specified, the .po file is created in the pathname directory. An existing .po file is overwritten.
Duplicate msgids are written to the .po file as comment lines. When the –s option is specified, the .po is sorted by the msgid string, and all duplicated msgids are removed. All msgstr directives in the .po file are empty unless the –m option is used.
The following options are supported:
Add comment lines to the output file indicating file name and line number in the source file where each extracted string is encountered. These lines appear before each msgid in the following format:
# # File: filename, line: line-number
Generate output sorted by msgids with all duplicate msgids removed.
Extract all strings, not just those found in gettext(3C), and dgettext() () calls. Only one .po file is created.
The comment block beginning with comment-tag as the first token of the comment block is added to the output .po file as # delimited comments. For multiple domains, xgettext directs comments and messages to the prevailing text domain.
Rename default output file from messages.po to default-domain .po.
Join messages with existing message files. If a .po file does not exist, it is created. If a .po file does exist, new messages are appended. Any duplicate msgids are commented out in the resulting .po file. Domain directives in the existing .po file are ignored. Results not guaranteed if the existing message file has been edited.
Fill in the msgstr with prefix. This is useful for debugging purposes. To make msgstr identical to msgid, use an empty string ("") for prefix.
Fill in the msgstr with suffix. This is useful for debugging purposes.
Specify the directory where the output files will be placed. This option overrides the current working directory.
Specify a .po file that contains a list of msgids that are not to be extracted from the input files. The format of exclude-file is identical to the .po file. However, only the msgid directive line in exclude-file is used. All other lines are simply ignored. The –x option can only be used with the –a option.
Print a help message on the standard output.
See attributes(7) for descriptions of the following attributes:
xgettext is not able to extract cast strings, for example ANSI C casts of literal strings to (const char *). This is unnecessary anyway, since the prototypes in <libintl.h> already specify this type.
In messages and translation notes, lines greater than 2048 characters are truncated to 2048 characters and a warning message is printed to stderr.