confstr(3) -- Linux man page

 

NAME

confstr - get configuration dependent string variables  

SYNOPSIS

#define _POSIX_C_SOURCE 2
or
#define _XOPEN_SOURCE
#include <unistd.h>

size_t confstr(int name, char *buf, size_t len);
 

DESCRIPTION

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.  

RETURN VALUE

If name does not correspond to a valid configuration variable, confstr() returns 0.  

EXAMPLES

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);
 

ERRORS

If the value of name is invalid, errno is set to EINVAL.  

CONFORMING TO

proposed POSIX.2  

BUGS

POSIX.2 is not yet an approved standard; the information in this manpage is subject to change.  

SEE ALSO

sh(1), exec(3), system(3)