NAME
getcwd, getwd
— get working directory
pathname
LIBRARY
library “libc”
SYNOPSIS
#include
<unistd.h>
char *
getcwd(char
*buf, size_t
size);
char *
getwd(char
*buf);
DESCRIPTION
Thegetcwd()
function copies the absolute pathname of the current working directory into
the memory referenced by buf and returns a pointer to
buf. The size argument is the
size, in bytes, of the array referenced by buf.
If buf is NULL,
space is allocated as necessary to store the pathname. This space may later
be free(3)'d.
The function
getwd() is a
compatibility routine which calls getcwd() with its
buf argument and a size of
MAXPATHLEN (as defined in the include file
<sys/param.h>). Obviously,
buf should be at least
MAXPATHLEN bytes in length.
These routines have traditionally been used by programs to save
the name of a working directory for the purpose of returning to it. A much
faster and less error-prone method of accomplishing this is to open the
current directory (‘.’) and use the
fchdir(2) function to return.
RETURN VALUES
Upon successful completion, a pointer to the pathname is returned.
Otherwise a NULL pointer is returned and the global
variable errno is set to indicate the error. In
addition, getwd() copies the error message
associated with errno into the memory referenced by
buf.
ERRORS
The getcwd() function will fail if:
- [
EACCES] - Read or search permission was denied for a component of the pathname.
- [
EINVAL] - The size argument is zero.
- [
ENOENT] - A component of the pathname no longer exists.
- [
ENOMEM] - Insufficient memory is available.
- [
ERANGE] - The size argument is greater than zero but smaller than the length of the pathname plus 1.
SEE ALSO
STANDARDS
The getcwd() function conforms to
IEEE Std 1003.1-1990 (“POSIX.1”). The
ability to specify a NULL pointer and have
getcwd() allocate memory as necessary is an
extension.
HISTORY
The getwd() function appeared in
4.0BSD.
BUGS
The getwd() function does not do
sufficient error checking and is not able to return very long, but valid,
paths. It is provided for compatibility.