Computer Science
GETCWD(3) Linux Programmer's Manual GETCWD(3)
NAME
getcwd, get_current_dir_name, getwd - Get current working
directory
SYNOPSIS
#include <unistd.h>
char *getcwd(char *buf, size_t size);
char *get_current_working_dir_name(void);
char *getwd(char *buf);
DESCRIPTION
The getcwd() function copies the absolute pathname of the
current working directory to the array pointed to by buf,
which is of length size.
If the current absolute path name would require a buffer
longer than size elements, NULL is returned, and errno is
set to ERANGE; an application should check for this error,
and allocate a larger buffer if necessary.
As an extension to the POSIX.1 standard, getcwd() allo-
cates the buffer dynamically using malloc() if buf is NULL
on call. In this case, the allocated buffer has the
length size unless size is less than zero, when buf is
allocated as big as necessary. It is possible (and,
indeed, advisable) to free() the buffers if they have been
obtained this way.
get_current_dir_name, which is only prototyped if
__USE_GNU is defined, will malloc(3) an array big enough
to hold the current directory name. If the environment
variable PWD is set, and its value is correct, then that
value will be returned.
getwd, which is only prototyped if __USE_BSD is defined,
will not malloc(3) any memory. The buf argument should be
a pointer to an array at least PATH_MAX bytes long. getwd
does only return the first PATH_MAX bytes of the actual
pathname.
RETURN VALUE
NULL on failure (for example, if the current directory is
not readable), with errno set accordingly, and buf on suc-
cess.
CONFORMING TO
POSIX.1
SEE ALSO
chdir(2), free(3), malloc(3).
GNU 21 July 1993 1
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