what [−s] file...
" > newline \ NUL
- Quit after finding the first occurrence of the pattern in each file.
- A pathname of a file to search.
- Provide a default value for the internationalization variables that are unset or null. (See the Base Definitions volume of POSIX.1‐2008, Section 8.2, Internationalization Variables for the precedence of internationalization variables used to determine the values of locale categories.)
- If set to a non-empty string value, override the values of all the other internationalization variables.
- Determine the locale for the interpretation of sequences of bytes of text data as characters (for example, single-byte as opposed to multi-byte characters in arguments and input files).
- Determine the location of message catalogs for the processing of LC_MESSAGES.
"%s:\n\t%s\n", <pathname>, <identification string>
- Any matches were found.
char ident = "@(#)identification information";
what f.c f.o a.out
f.c: identification information ... f.o: identification information ... a.out: identification information ...