HP-UX HB v13.00 Ch-11 - Software Development

HP-UX Handbook – Rev 13.00 Page 51 (of 101)
Chapter 11 Software Development
October 29, 2013
Static Information
file(1)
The file(1) command tries to determine the type of a file by checking magic(4) numbers. On
ascii files it analyzes the first lines and tries to guess a programming language, if any.
If you have compiled a C program named a.out which was compiled from a source file named
x.c, and which unfortunately aborted with a coredump, file(1) will give an output similar to
the following:
$ file x.c x.o a.out core
On PA:
x.c: c program text
x.o: PA-RISC2.0 relocatable object
a.out: PA-RISC2.0 shared executable dynamically linked –not stripped
core: core file from 'a.out' - received SIGBUS
On IA:
x.c: c program text
x.o: ELF-32 relocatable object file - IA64
a.out: ELF-32 executable object file - IA64
core: ELF-32 core file - IA64 from 'a.out' - received SIGBUS
The output for the core file is epecially interesting, because it provides information on what
happened. It tells you:
 Which program generated the core file
 Why the core file was generated (which signal was received)
file(1) belongs to the unix core commands.
what(1)
what(1) can be used to find out the version of a file. It belongs to SCCS. Every file shipped by
HP that requires versioning contains a text that can be printed by the what(1) command. A
what-string can be added to any file. It is simply a character string that starts with "@(#)" to be
recognized by what(1).
If you add the line
char ident[] = "@(#) x.c version 0.1 from Jan 04 2002";
to a C program source file, compile and run it, the what string will be in every file created from
it, even in a coredump: