check_utility_compat - "determine whether a utility should be compatible"
Library Synopsis Description Return Values Files Errors History Authors
.In unistd.h int check_utility_compat "const char *utility"
The check_utility_compat function checks whether utility should behave in a traditional (Fx 4.7 -compatible) manner, or in accordance with -p1003.1-2001. The configuration is given as a comma-separated list of utility names; if the list is present but empty, all supported utilities assume their most compatible mode. The check_utility_compat function first checks for an environment variable named _COMPAT_FreeBSD_4. If that environment variable does not exist, then check_utility_compat will attempt to read the contents of a symbolic link named /etc/compat-FreeBSD-4-util. If no configuration is found, compatibility mode is disabled.
The check_utility_compat function returns zero if utility should implement strict -p1003.1-2001 behavior, and nonzero otherwise.