CONFSTR(3) Library Functions Manual CONFSTR(3)
confstr -- get string-valued configurable variables
Standard C Library (libc, -lc)
confstr(int name, char *buf, size_t len);
This interface is obsoleted by sysctl(3).
The confstr() function provides a method for applications to get
configuration 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:
Return a value for the PATH environment variable that finds all
the standard utilities.
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.
The confstr function may fail and set error 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.
The confstr function conforms to IEEE Std 1003.2-1992 (``POSIX.2'').
The confstr function first appeared in 4.4BSD.
The standards require us to return 0 both on errors, and when the value
is not set.
NetBSD 6.1.5 April 22, 2010 NetBSD 6.1.5