NAME¶
explain_getpgrp_or_die - get process group and report errors
SYNOPSIS¶
#include <libexplain/getpgrp.h>
pid_t explain_getpgrp_or_die(pid_t pid);
pid_t explain_getpgrp_on_error(pid_t pid);
DESCRIPTION¶
The
explain_getpgrp_or_die function is used to call the
getpgrp(2)
system call. On failure an explanation will be printed to
stderr,
obtained from the
explain_getpgrp(3) function, and then the process
terminates by calling exit(EXIT_FAILURE).
The
explain_getpgrp_on_error function is used to call the
getpgrp(2) system call. On failure an explanation will be printed to
stderr, obtained from the
explain_getpgrp(3) function, but still
returns to the caller.
- pid
- The pid, exactly as to be passed to the getpgrp(2)
system call.
API Inconsistencies¶
Note: the
getpgrp(2) function has two implementations. The POSIX.1
version has no arguments, while the BSD version has one argument. For
simplicity of implementation, the argument list seen here includes the
pid argument.
The POSIX.1 getpgid() semanatics can be obtained by calling getpgrp(0) on BSD
systems, and this is the API for libexplain, even on systems that do not use
the BSD API.
RETURN VALUE¶
The
explain_getpgrp_or_die function only returns on success, see
getpgrp(2) for more information. On failure, prints an explanation and
exits, it does not return.
The
explain_getpgrp_on_error function always returns the value return by
the wrapped
getpgrp(2) system call.
EXAMPLE¶
The
explain_getpgrp_or_die function is intended to be used in a fashion
similar to the following example:
pid_t result = explain_getpgrp_or_die(pid);
SEE ALSO¶
- getpgrp(2)
- get process group
- explain_getpgrp(3)
- explain getpgrp(2) errors
- exit(2)
- terminate the calling process
COPYRIGHT¶
libexplain version 0.52
Copyright (C) 2011 Peter Miller