Originální popis anglicky:
confstr - get configuration dependent string variables
Návod, kniha: Linux Programmer's Manual
#define _POSIX_C_SOURCE 2
or
#define _XOPEN_SOURCE
#include <unistd.h>
size_t confstr(int name, char *buf, size_t len);
confstr() gets the value of configuration-dependent string variables.
The
name argument is the system variable to be queried. The following
variables are supported:
- _CS_PATH
- A value for the PATH variable which indicates where
all the POSIX.2 standard utilities can be found.
If
buf is not
NULL, and
len is not zero,
confstr()
copies the value of the string to
buf truncated to
len - 1
characters if necessary, with a null character as termination. This can be
detected by comparing the return value of
confstr() against
len.
If
len is zero and
buf is
NULL,
confstr() just
returns the value as defined below.
If
name does not correspond to a valid configuration variable,
confstr() returns 0.
The following code fragment determines the path where to find the POSIX.2 system
utilities:
char *pathbuf; size_t n;
n = confstr(_CS_PATH,NULL,(size_t)0);
if ((pathbuf = malloc(n)) == NULL) abort();
confstr(_CS_PATH, pathbuf, n);
If the value of
name is invalid,
errno is set to
EINVAL.
proposed POSIX.2
POSIX.2 is not yet an approved standard; the information in this manpage is
subject to change.
sh(1),
exec(3),
system(3)
