xgettext options and examples

SYNOPSIS
    xgettext - extract gettext strings from source
     xgettext [OPTION] [INPUTFILE]
DESCRIPTION
• Extract translatable strings from given input files.
• Mandatory arguments to long options are mandatory for short options too. Similarly for optional arguments.
Input files location:
INPUTFILE ...
input files
• -f, --files-from=FILE
    get list of input files from FILE
• -D, --directory=DIRECTORY
    add DIRECTORY to list for input files search
If input file is -, standard input is read.
Output files location:
• -d, --default-domain=NAME
    use NAME.po for output (instead of messages.po)
• -o, --output=FILE
    write output to specified file
• -p, --output-dir=DIR
    output files will be placed in directory DIR
If output file is -, output is written to standard output.
Choice of input file language:
• -L, --language=NAME
    recognise the specified language (C, C++, ObjectiveC, PO, Shell, Python, Lisp, EmacsLisp, librep, Scheme, Smalltalk, Java, JavaProperties, C#, awk, YCP, Tcl, Perl, PHP, GCC-source, NXStringTable, RST, Glade)
• -C, --c++ shorthand for --language=C++
By default the language is guessed depending on the input file name extension.
Input file interpretation:
• --from-code=NAME
    encoding of input files (except for Python, Tcl, Glade)
By default the input files are assumed to be in ASCII.
Operation mode:
• -j, --join-existing
    join messages with existing file
• -x, --exclude-file=FILE.po
    entries from FILE.po are not extracted
• -c, --add-comments[=TAG]
    place comment block with TAG (or those preceding keyword lines) in output file
Language specific options:
• -a, --extract-all
    extract all strings (only languages C, C++, ObjectiveC, Shell, Python, Lisp, EmacsLisp, librep, Scheme, Java, C#, awk, Tcl, Perl, PHP, GCC-source, Glade)
• -k, --keyword[=WORD]
    additional keyword to be looked for (without WORD means not to use default keywords)
(only languages C, C++, ObjectiveC, Shell, Python, Lisp, EmacsLisp, librep, Scheme, Java, C#, awk, Tcl, Perl, PHP, GCC-source, Glade)
• --flag=WORD:ARG:FLAG
    additional flag for strings inside the argument number ARG of keyword WORD
(only languages C, C++, ObjectiveC, Shell, Python, Lisp, EmacsLisp, librep, Scheme, Java, C#, awk, YCP, Tcl, Perl, PHP, GCC-source)
• -T, --trigraphs
    understand ANSI C trigraphs for input (only languages C, C++, ObjectiveC)
• --qt recognize Qt format strings (only language C++)
• --kde recognize KDE 4 format strings (only language C++)
• --boost recognize Boost format strings (only language C++)
• --debug more detailed formatstring recognition result
Output details:
• -e, --no-escape
    do not use C escapes in output (default)
• -E, --escape
    use C escapes in output, no extended chars
• --force-po
    write PO file even if empty
• -i, --indent
    write the .po file using indented style
• --no-location
    do not write ’#: filename:line’ lines
• -n, --add-location
    generate ’#: filename:line’ lines (default)
• --strict
    write out strict Uniforum conforming .po file
• --properties-output
    write out a Java .properties file
• --stringtable-output
    write out a NeXTstep/GNUstep .strings file
• -w, --width=NUMBER
    set output page width
• --no-wrap do not break long message lines, longer than the output page width, into several lines
• -s, --sort-output
    generate sorted output
• -F, --sort-by-file
    sort output by file location
• --omit-header
    don’t write header with ‘msgid ""’ entry
• --copyright-holder=STRING
    set copyright holder in output
• --foreign-user
    omit FSF copyright in output for foreign user
• --package-name=PACKAGE
    set package name in output
• --package-version=VERSION
    set package version in output
• --msgid-bugs-address=EMAIL@ADDRESS
    set report address for msgid bugs
• -m, --msgstr-prefix[=STRING]
    use STRING or "" as prefix for msgstr entries
• -M, --msgstr-suffix[=STRING]
    use STRING or "" as suffix for msgstr entries
Informative output:
• -h, --help display this help and exit
• -V, --version
output version information and exit
Examples:
• xgettext -o myapp.po -p ./locale --force-po --from-code=UTF-8 --keyword --keyword=__ --keyword=gettext -L PHP *.php
• xgettext –a abc.php // specific file
• xgettext –a *.php // All file

refrence: http://www.gsp.com/cgi-bin/man.cgi?section=1&topic=xgettext