Section (1) realpath
realpath — print the resolved path
Print the resolved absolute file name; all but the last component must exist
all components of the path must exist
no path components need exist or be a directory
resolve _zsingle_quotesz_.._zsingle_quotesz_ components before symlinks
resolve symlinks as encountered (default)
suppress most error messages
print the resolved path relative to DIR
print absolute paths unless paths below DIR
don_zsingle_quotesz_t expand symlinks
end each output line with NUL, not newline
display this help and exit
output version information and exit
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
Full documentation <https://www.gnu.org/software/coreutils/realpath>
or available locally via: info _zsingle_quotesz_(coreutils) realpath invocation_zsingle_quotesz_
Copyright © 2019 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
Section (3) realpath
realpath — return the canonicalized absolute pathname
#include <limits.h> #include <stdlib.h>
||const char *path,|
realpath() expands all
symbolic links and resolves references to
extra _zsingle_quotesz_/_zsingle_quotesz_ characters in the null-terminated string named by
path to produce a
canonicalized absolute pathname. The resulting pathname is
stored as a null-terminated string, up to a maximum of
PATH_MAX bytes, in the buffer
pointed to by
resolved_path. The resulting
path will have no symbolic link,
is specified as NULL, then
realpath() uses malloc(3) to allocate a
buffer of up to
to hold the resolved pathname, and returns a pointer to this
buffer. The caller should deallocate this buffer using
If there is no error,
realpath() returns a pointer to the
Otherwise, it returns NULL, the contents of the array
errno is set to
indicate the error.
Read or search permission was denied for a component of the path prefix.
pathis NULL. (In glibc versions before 2.3, this error is also returned if
An I/O error occurred while reading from the filesystem.
Too many symbolic links were encountered in translating the pathname.
A component of a pathname exceeded
NAME_MAXcharacters, or an entire pathname exceeded
The named file does not exist.
Out of memory.
A component of the path prefix is not a directory.
For an explanation of the terms used in this section, see attributes(7).
POSIX.1-2001 says that the behavior if
resolved_path is NULL is
implementation-defined. POSIX.1-2008 specifies the behavior
described in this page.
In 4.4BSD and Solaris, the limit on the pathname length is
MAXPATHLEN (found in
> SUSv2 prescribes
NAME_MAX, as found in
or provided by the pathconf(3) function. A
typical source fragment would be
#ifdef PATH_MAX path_max = PATH_MAX; #else path_max = pathconf(path, _PC_PATH_MAX); if (path_max <= 0) path_max = 4096; #endif
(But see the BUGS section.)
The POSIX.1-2001 standard version of this function is
broken by design, since it is impossible to determine a
suitable size for the output buffer,
resolved_path. According to
POSIX.1-2001 a buffer of size
PATH_MAX suffices, but
PATH_MAX need not be a defined constant,
and may have to be obtained using pathconf(3). And asking
pathconf(3) does not really
help, since, on the one hand POSIX warns that the result of
pathconf(3) may be huge and
unsuitable for mallocing memory, and on the other hand
pathconf(3) may return
−1 to signify that
PATH_MAX is not bounded. The resolved_path == NULL feature, not
standardized in POSIX.1-2001, but standardized in
POSIX.1-2008, allows this design problem to be avoided.
This page is part of release 4.16 of the Linux
man-pages project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
Copyright (C) 1999 Andries Brouwer (aebcwi.nl)
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Rewritten old page, 990824, aebcwi.nl
2004-12-14, mtk, added discussion of resolved_path == NULL