|
Packit |
7cfc04 |
'\" et
|
|
Packit |
7cfc04 |
.TH DIRNAME "3P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual"
|
|
Packit |
7cfc04 |
.SH PROLOG
|
|
Packit |
7cfc04 |
This manual page is part of the POSIX Programmer's Manual.
|
|
Packit |
7cfc04 |
The Linux implementation of this interface may differ (consult
|
|
Packit |
7cfc04 |
the corresponding Linux manual page for details of Linux behavior),
|
|
Packit |
7cfc04 |
or the interface may not be implemented on Linux.
|
|
Packit |
7cfc04 |
|
|
Packit |
7cfc04 |
.SH NAME
|
|
Packit |
7cfc04 |
dirname
|
|
Packit |
7cfc04 |
\(em report the parent directory name of a file pathname
|
|
Packit |
7cfc04 |
.SH SYNOPSIS
|
|
Packit |
7cfc04 |
.LP
|
|
Packit |
7cfc04 |
.nf
|
|
Packit |
7cfc04 |
#include <libgen.h>
|
|
Packit |
7cfc04 |
.P
|
|
Packit |
7cfc04 |
char *dirname(char *\fIpath\fP);
|
|
Packit |
7cfc04 |
.fi
|
|
Packit |
7cfc04 |
.SH DESCRIPTION
|
|
Packit |
7cfc04 |
The
|
|
Packit |
7cfc04 |
\fIdirname\fR()
|
|
Packit |
7cfc04 |
function shall take a pointer to a character string that contains a
|
|
Packit |
7cfc04 |
pathname, and return a pointer to a string that is a pathname of the
|
|
Packit |
7cfc04 |
parent directory of that file. Trailing
|
|
Packit |
7cfc04 |
.BR '/'
|
|
Packit |
7cfc04 |
characters in the path are not counted as part of the path.
|
|
Packit |
7cfc04 |
.P
|
|
Packit |
7cfc04 |
If
|
|
Packit |
7cfc04 |
.IR path
|
|
Packit |
7cfc04 |
does not contain a
|
|
Packit |
7cfc04 |
.BR '/' ,
|
|
Packit |
7cfc04 |
then
|
|
Packit |
7cfc04 |
\fIdirname\fR()
|
|
Packit |
7cfc04 |
shall return a pointer to the string
|
|
Packit |
7cfc04 |
.BR \(dq.\(dq .
|
|
Packit |
7cfc04 |
If
|
|
Packit |
7cfc04 |
.IR path
|
|
Packit |
7cfc04 |
is a null pointer or points to an empty string,
|
|
Packit |
7cfc04 |
\fIdirname\fR()
|
|
Packit |
7cfc04 |
shall return a pointer to the string
|
|
Packit |
7cfc04 |
.BR \(dq.\(dq .
|
|
Packit |
7cfc04 |
.P
|
|
Packit |
7cfc04 |
The
|
|
Packit |
7cfc04 |
\fIdirname\fR()
|
|
Packit |
7cfc04 |
function need not be thread-safe.
|
|
Packit |
7cfc04 |
.SH "RETURN VALUE"
|
|
Packit |
7cfc04 |
The
|
|
Packit |
7cfc04 |
\fIdirname\fR()
|
|
Packit |
7cfc04 |
function shall return a pointer to a string that is the parent
|
|
Packit |
7cfc04 |
directory of
|
|
Packit |
7cfc04 |
.IR path .
|
|
Packit |
7cfc04 |
If
|
|
Packit |
7cfc04 |
.IR path
|
|
Packit |
7cfc04 |
is a null pointer or points to an empty string, a pointer to a string
|
|
Packit |
7cfc04 |
.BR \(dq.\(dq
|
|
Packit |
7cfc04 |
is returned.
|
|
Packit |
7cfc04 |
.P
|
|
Packit |
7cfc04 |
The
|
|
Packit |
7cfc04 |
\fIdirname\fR()
|
|
Packit |
7cfc04 |
function may modify the string pointed to by
|
|
Packit |
7cfc04 |
.IR path ,
|
|
Packit |
7cfc04 |
and may return a pointer to internal storage. The returned pointer might
|
|
Packit |
7cfc04 |
be invalidated or the storage might be overwritten by a subsequent call to
|
|
Packit |
7cfc04 |
\fIdirname\fR().
|
|
Packit |
7cfc04 |
.SH ERRORS
|
|
Packit |
7cfc04 |
No errors are defined.
|
|
Packit |
7cfc04 |
.LP
|
|
Packit |
7cfc04 |
.IR "The following sections are informative."
|
|
Packit |
7cfc04 |
.SH EXAMPLES
|
|
Packit |
7cfc04 |
The following code fragment reads a pathname, changes the current
|
|
Packit |
7cfc04 |
working directory to the parent directory, and opens the file.
|
|
Packit |
7cfc04 |
.sp
|
|
Packit |
7cfc04 |
.RS 4
|
|
Packit |
7cfc04 |
.nf
|
|
Packit |
7cfc04 |
\fB
|
|
Packit |
7cfc04 |
char *path = NULL, *pathcopy;
|
|
Packit |
7cfc04 |
size_t buflen = 0;
|
|
Packit |
7cfc04 |
ssize_t linelen = 0;
|
|
Packit |
7cfc04 |
int fd;
|
|
Packit |
7cfc04 |
.P
|
|
Packit |
7cfc04 |
linelen = getline(&path, &buflen, stdin);
|
|
Packit |
7cfc04 |
.P
|
|
Packit |
7cfc04 |
path[linelen-1] = 0;
|
|
Packit |
7cfc04 |
pathcopy = strdup(path);
|
|
Packit |
7cfc04 |
if (chdir(dirname(pathcopy)) < 0) {
|
|
Packit |
7cfc04 |
...
|
|
Packit |
7cfc04 |
}
|
|
Packit |
7cfc04 |
if ((fd = open(basename(path), O_RDONLY)) >= 0) {
|
|
Packit |
7cfc04 |
...
|
|
Packit |
7cfc04 |
close (fd);
|
|
Packit |
7cfc04 |
}
|
|
Packit |
7cfc04 |
\&...
|
|
Packit |
7cfc04 |
free (pathcopy);
|
|
Packit |
7cfc04 |
free (path);
|
|
Packit |
7cfc04 |
.fi \fR
|
|
Packit |
7cfc04 |
.P
|
|
Packit |
7cfc04 |
.RE
|
|
Packit |
7cfc04 |
.SS "Sample Input and Output Strings for dirname(\|)"
|
|
Packit |
7cfc04 |
.P
|
|
Packit |
7cfc04 |
In the following table, the input string is the value pointed to by
|
|
Packit |
7cfc04 |
.IR path ,
|
|
Packit |
7cfc04 |
and the output string is the return value of the
|
|
Packit |
7cfc04 |
\fIdirname\fR()
|
|
Packit |
7cfc04 |
function.
|
|
Packit |
7cfc04 |
.TS
|
|
Packit |
7cfc04 |
center tab(!) box;
|
|
Packit |
7cfc04 |
cB | cB
|
|
Packit |
7cfc04 |
lf5 | lf5.
|
|
Packit |
7cfc04 |
Input String!Output String
|
|
Packit |
7cfc04 |
_
|
|
Packit |
7cfc04 |
"/usr/lib"!"/usr"
|
|
Packit |
7cfc04 |
"/usr/"!"/"
|
|
Packit |
7cfc04 |
"usr"!"."
|
|
Packit |
7cfc04 |
"/"!"/"
|
|
Packit |
7cfc04 |
"."!"."
|
|
Packit |
7cfc04 |
".."!"."
|
|
Packit |
7cfc04 |
.TE
|
|
Packit |
7cfc04 |
.SH "APPLICATION USAGE"
|
|
Packit |
7cfc04 |
The
|
|
Packit |
7cfc04 |
\fIdirname\fR()
|
|
Packit |
7cfc04 |
and
|
|
Packit |
7cfc04 |
\fIbasename\fR()
|
|
Packit |
7cfc04 |
functions together yield a complete pathname. The expression
|
|
Packit |
7cfc04 |
\fIdirname\fP\^(\fIpath\fP) obtains the pathname of the directory where
|
|
Packit |
7cfc04 |
\fIbasename\fP\^(\fIpath\fP) is found.
|
|
Packit |
7cfc04 |
.P
|
|
Packit |
7cfc04 |
Since the meaning of the leading
|
|
Packit |
7cfc04 |
.BR \(dq//\(dq
|
|
Packit |
7cfc04 |
is implementation-defined,
|
|
Packit |
7cfc04 |
.IR dirname ("\c
|
|
Packit |
7cfc04 |
.BR //foo ")
|
|
Packit |
7cfc04 |
may return either
|
|
Packit |
7cfc04 |
.BR \(dq//\(dq
|
|
Packit |
7cfc04 |
or
|
|
Packit |
7cfc04 |
.BR '/'
|
|
Packit |
7cfc04 |
(but nothing else).
|
|
Packit |
7cfc04 |
.SH RATIONALE
|
|
Packit |
7cfc04 |
None.
|
|
Packit |
7cfc04 |
.SH "FUTURE DIRECTIONS"
|
|
Packit |
7cfc04 |
None.
|
|
Packit |
7cfc04 |
.SH "SEE ALSO"
|
|
Packit |
7cfc04 |
.IR "\fIbasename\fR\^(\|)"
|
|
Packit |
7cfc04 |
.P
|
|
Packit |
7cfc04 |
The Base Definitions volume of POSIX.1\(hy2008,
|
|
Packit |
7cfc04 |
.IR "\fB<libgen.h>\fP"
|
|
Packit |
7cfc04 |
.SH COPYRIGHT
|
|
Packit |
7cfc04 |
Portions of this text are reprinted and reproduced in electronic form
|
|
Packit |
7cfc04 |
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
|
|
Packit |
7cfc04 |
-- Portable Operating System Interface (POSIX), The Open Group Base
|
|
Packit |
7cfc04 |
Specifications Issue 7, Copyright (C) 2013 by the Institute of
|
|
Packit |
7cfc04 |
Electrical and Electronics Engineers, Inc and The Open Group.
|
|
Packit |
7cfc04 |
(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
|
|
Packit |
7cfc04 |
event of any discrepancy between this version and the original IEEE and
|
|
Packit |
7cfc04 |
The Open Group Standard, the original IEEE and The Open Group Standard
|
|
Packit |
7cfc04 |
is the referee document. The original Standard can be obtained online at
|
|
Packit |
7cfc04 |
http://www.unix.org/online.html .
|
|
Packit |
7cfc04 |
|
|
Packit |
7cfc04 |
Any typographical or formatting errors that appear
|
|
Packit |
7cfc04 |
in this page are most likely
|
|
Packit |
7cfc04 |
to have been introduced during the conversion of the source files to
|
|
Packit |
7cfc04 |
man page format. To report such errors, see
|
|
Packit |
7cfc04 |
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
|