Message selection:
[-N SOURCEFILE]... [-M DOMAINNAME]...
[-K MSGID-PATTERN] [-T MSGSTR-PATTERN] [-C COMMENT-PATTERN]
A message is selected if it comes from one of the specified source files,
or if it comes from one of the specified domains,
or if -K is given and its key (msgid or msgid_plural) matches MSGID-PATTERN,
or if -T is given and its translation (msgstr) matches MSGSTR-PATTERN,
or if -C is given and the translator's comment matches COMMENT-PATTERN.
When more than one selection criterion is specified, the set of selected
messages is the union of the selected messages of each criterion.
MSGID-PATTERN or MSGSTR-PATTERN or COMMENT-PATTERN syntax:
[-E | -F] [-e PATTERN | -f FILE]...
PATTERNs are basic regular expressions by default, or extended regular
expressions if -E is given, or fixed strings if -F is given.
-N, --location=SOURCEFILE select messages extracted from SOURCEFILE
-M, --domain=DOMAINNAME select messages belonging to domain DOMAINNAME
-K, --msgid start of patterns for the msgid
-T, --msgstr start of patterns for the msgstr
-C, --comment start of patterns for the translator's comment
-E, --extended-regexp PATTERN is an extended regular expression
-F, --fixed-strings PATTERN is a set of newline-separated strings
-e, --regexp=PATTERN use PATTERN as a regular expression
-f, --file=FILE obtain PATTERN from FILE
-i, --ignore-case ignore case distinctions
