CONFSTR(3) BSD Library Functions Manual CONFSTR(3)NAMEconfstr — get string-valued configurable variables
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <unistd.h>
size_t
confstr(int name, char *buf, size_t len);
DESCRIPTION
This interface is obsoleted by sysctl(3).
The confstr() function provides a method for applications to get configu‐
ration defined string values.
The name argument specifies the system variable to be queried. Symbolic
constants for each name value are found in the <unistd.h> header. 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 PATH environment 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 error for any of the errors speci‐
fied 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 ALSOsysctl(3)STANDARDS
The confstr function conforms to IEEE Std 1003.2-1992 (“POSIX.2”).
HISTORY
The confstr function first appeared in 4.4BSD.
BUGS
The standards require us to return 0 both on errors, and when the value
is not set.
BSD April 22, 2010 BSD
