program_invocation_name(3) - Linux man page
Name
program_invocation_name, program_invocation_short_name - obtain name used to invoke calling programSynopsis
#define _GNU_SOURCE /* See feature_test_macros(7) */#include <errno.h>extern char *program_invocation_name;extern char *program_invocation_short_name;
Description
program_invocation_name contains the name that was used to invoke the calling program. This is the same as the value of argv[0] in main(), with the difference that the scope of program_invocation_name is global.program_invocation_short_name contains the basename component of name that was used to invoke the calling program. That is, it is the same value as program_invocation_name, with all text up to and including the final slash (/), if any, removed.
These variables are automatically initialized by the glibc run-time startup code.