NAME
confstr —
get string-valued configurable
variables
LIBRARY
library “libc”
SYNOPSIS
#include
<unistd.h>
size_t
confstr(int
name, char *buf,
size_t len);
DESCRIPTION
This interface is specified by IEEE Std 1003.1-2001 (“POSIX.1”). A more flexible (but non-portable) interface is provided by sysctl(3).The
confstr()
function provides a method for applications to get configuration defined
string values. Shell programmers needing access to these parameters should
use the getconf(1) utility.
The name argument specifies the system
variable to be queried. Symbolic constants for each name value are found in
the include file <unistd.h>.
The len argument specifies the size of the buffer
referenced by the argument buf. If
len is non-zero, buf is a
non-null pointer, and name has a value, up to
len - 1 bytes of the value are copied into the buffer
buf. The copied value is always null terminated.
The available values are as follows:
_CS_PATH- Return a value for the
PATHenvironment variable that finds all the standard utilities.
RETURN VALUES
If the call to confstr() is not
successful, 0 is returned and errno is set
appropriately. Otherwise, if the variable does not have a configuration
defined value, 0 is returned and errno is not
modified. Otherwise, the buffer size needed to hold the entire
configuration-defined value is returned. If this size is greater than the
argument len, the string in buf
was truncated.
ERRORS
The confstr() function may fail and set
errno for any of the errors specified for the library
functions malloc(3) and
sysctl(3).
In addition, the following errors may be reported:
- [
EINVAL] - The value of the name argument is invalid.
SEE ALSO
STANDARDS
The confstr() function conforms to
Version 3 of the Single UNIX Specification
(“SUSv3”).
HISTORY
The confstr() function first appeared in
4.4BSD.