CONFSTR(3) | Library Functions Manual | CONFSTR(3) |
confstr
— get
string-valued configurable variables
Standard C Library (libc, -lc)
#include
<unistd.h>
size_t
confstr
(int
name, char *buf,
size_t len);
This interface is specified by POSIX. 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_DARWIN_USER_DIR
This directory is created with access permissions of 0755 and restricted by the umask(2) of the calling process and is not intended to be used for sensitive or temporary file storage, as all users can see files created here. If the user's umask allows it, files created here will be world readable, which could lead to information disclosure.
_CS_DARWIN_USER_TEMP_DIR
By default, files in this location may be cleaned (removed) by the system if they are not accessed in 3 days.
_CS_DARWIN_USER_CACHE_DIR
Files in this location will be removed during safe boot.
_CS_PATH
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
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
]ENOMEM
]EIO
]If the call to
confstr
()
is not successful, -1 (rather than 0) is returned and
errno is set appropriately.
The confstr
() function first appeared in
4.4BSD.
June 18, 2001 | macOS 14.6 |