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 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 configu‐
ration 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 argu‐
ment 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 configura‐
tion 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 spec‐
ified 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 ALSOgetconf(1), pathconf(2), sysconf(3), sysctl(3)HISTORY
The confstr() function first appeared in 4.4BSD.
BSD December 3, 2006 BSD
