NAME

       getcwd, getwd, get_current_dir_name - get current working directory

SYNOPSIS

       #include <unistd.h>

       char *getcwd(char *buf, size_t size);

       char *getwd(char *buf);

       char *get_current_dir_name(void);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       get_current_dir_name():
              _GNU_SOURCE

       getwd():
           Since glibc 2.12:
               _BSD_SOURCE ||
                   (_XOPEN_SOURCE >= 500 ||
                       _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED) &&
                   !(_POSIX_C_SOURCE >= 200809L || _XOPEN_SOURCE >= 700)
           Before glibc 2.12:
               _BSD_SOURCE || _XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED

DESCRIPTION

       These  functions  return  a  null-terminated  string  containing an absolute pathname that is the current
       working directory of the calling process.  The pathname is returned as the function result  and  via  the
       argument buf, if present.

       The  getcwd()  function copies an absolute pathname of the current working directory to the array pointed
       to by buf, which is of length size.

       If the length of the absolute pathname of the current working directory, including the  terminating  null
       byte,  exceeds  size bytes, 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.1-2001 standard, Linux (libc4, libc5, glibc) getcwd() allocates  the  buffer
       dynamically  using  malloc(3)  if  buf  is  NULL.  In this case, the allocated buffer has the length size
       unless size is zero, when buf is allocated as big as necessary.  The caller should free(3)  the  returned
       buffer.

       get_current_dir_name()  will  malloc(3)  an array big enough to hold the absolute pathname of the current
       working directory.  If the environment variable PWD is set, and its value is  correct,  then  that  value
       will be returned.  The caller should free(3) the returned buffer.

       getwd()  does  not  malloc(3)  any  memory.   The  buf  argument should be a pointer to an array at least
       PATH_MAX bytes long.  If the length of the absolute pathname of the current working directory,  including
       the  terminating  null  byte, exceeds PATH_MAX bytes, NULL is returned, and errno is set to ENAMETOOLONG.
       (Note that on some systems, PATH_MAX may not be a  compile-time  constant;  furthermore,  its  value  may
       depend  on  the  filesystem,  see  pathconf(3).)  For portability and security reasons, use of getwd() is
       deprecated.

RETURN VALUE

       On success, these functions return a pointer to a string containing the pathname of the  current  working
       directory.  In the case getcwd() and getwd() this is the same value as buf.

       On  failure,  these  functions  return NULL, and errno is set to indicate the error.  The contents of the
       array pointed to by buf are undefined on error.

ERRORS

       EACCES Permission to read or search a component of the filename was denied.

       EFAULT buf points to a bad address.

       EINVAL The size argument is zero and buf is not a NULL pointer.

       EINVAL getwd(): buf is NULL.

       ENAMETOOLONG
              getwd(): The size of the null-terminated absolute pathname string exceeds PATH_MAX bytes.

       ENOENT The current working directory has been unlinked.

       ERANGE The size argument is less than the length of the  absolute  pathname  of  the  working  directory,
              including the terminating null byte.  You need to allocate a bigger array and try again.

CONFORMING TO

       getcwd()  conforms  to  POSIX.1-2001.   Note  however  that  POSIX.1-2001 leaves the behavior of getcwd()
       unspecified if buf is NULL.

       getwd() is present in POSIX.1-2001,  but  marked  LEGACY.   POSIX.1-2008  removes  the  specification  of
       getwd().  Use getcwd() instead.  POSIX.1-2001 does not define any errors for getwd().

       get_current_dir_name() is a GNU extension.

NOTES

       Under  Linux,  the  function  getcwd()  is a system call (since 2.1.92).  On older systems it would query
       /proc/self/cwd.  If both system call and proc filesystem are missing, a generic implementation is called.
       Only in that case can these calls fail under Linux with EACCES.

       These  functions  are often used to save the location of the current working directory for the purpose of
       returning to it later.  Opening the current directory (".") and calling fchdir(2) to return is usually  a
       faster and more reliable alternative when sufficiently many file descriptors are available, especially on
       platforms other than Linux.

SEE ALSO

       chdir(2), fchdir(2), open(2), unlink(2), free(3), malloc(3)

COLOPHON

       This page is part of release 3.54 of the Linux man-pages project.  A  description  of  the  project,  and
       information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.