mirror of https://github.com/mkerrisk/man-pages
110 lines
3.5 KiB
Plaintext
110 lines
3.5 KiB
Plaintext
.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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.TH "TEMPNAM" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
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.\" tempnam
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.SH NAME
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tempnam \- create a name for a temporary file
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.SH SYNOPSIS
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.LP
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\fB#include <stdio.h>
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.br
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.sp
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char *tempnam(const char *\fP\fIdir\fP\fB, const char *\fP\fIpfx\fP\fB);
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\fP
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\fB
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.br
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\fP
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.SH DESCRIPTION
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.LP
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The \fItempnam\fP() function shall generate a pathname that may be
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used for a temporary file.
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.LP
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The \fItempnam\fP() function allows the user to control the choice
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of a directory. The \fIdir\fP argument points to the name
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of the directory in which the file is to be created. If \fIdir\fP
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is a null pointer or points to a string which is not a name for
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an appropriate directory, the path prefix defined as P_tmpdir in the
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\fI<stdio.h>\fP
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header shall be used. If that directory is not accessible, an implementation-defined
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directory may be used.
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.LP
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Many applications prefer their temporary files to have certain initial
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letter sequences in their names. The \fIpfx\fP argument
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should be used for this. This argument may be a null pointer or point
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to a string of up to five bytes to be used as the beginning
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of the filename.
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.LP
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Some implementations of \fItempnam\fP() may use \fItmpnam\fP() internally.
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On such
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implementations, if called more than {TMP_MAX} times in a single process,
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the behavior is implementation-defined.
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.SH RETURN VALUE
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.LP
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Upon successful completion, \fItempnam\fP() shall allocate space for
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a string, put the generated pathname in that space, and
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return a pointer to it. The pointer shall be suitable for use in a
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subsequent call to \fIfree\fP(). Otherwise, it shall return a null
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pointer and set \fIerrno\fP to indicate the
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error.
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.SH ERRORS
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.LP
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The \fItempnam\fP() function shall fail if:
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.TP 7
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.B ENOMEM
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Insufficient storage space is available.
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.sp
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.LP
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\fIThe following sections are informative.\fP
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.SH EXAMPLES
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.SS Generating a Pathname
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.LP
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The following example generates a pathname for a temporary file in
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directory \fB/tmp\fP, with the prefix \fIfile\fP. After the
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filename has been created, the call to \fIfree\fP() deallocates the
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space used to store the
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filename.
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.sp
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.RS
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.nf
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\fB#include <stdio.h>
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#include <stdlib.h>
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\&...
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char *directory = "/tmp";
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char *fileprefix = "file";
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char *file;
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.sp
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file = tempnam(directory, fileprefix);
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free(file);
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\fP
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.fi
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.RE
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.SH APPLICATION USAGE
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.LP
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This function only creates pathnames. It is the application's responsibility
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to create and remove the files. Between the time a
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pathname is created and the file is opened, it is possible for some
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other process to create a file with the same name. Applications
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may find \fItmpfile\fP() more useful.
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.SH RATIONALE
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.LP
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None.
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.SH FUTURE DIRECTIONS
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.LP
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None.
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.SH SEE ALSO
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.LP
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\fIfopen\fP() , \fIfree\fP() , \fIopen\fP() , \fItmpfile\fP() , \fItmpnam\fP()
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, \fIunlink\fP() ,
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the Base Definitions volume of IEEE\ Std\ 1003.1-2001, \fI<stdio.h>\fP
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.SH COPYRIGHT
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Portions of this text are reprinted and reproduced in electronic form
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from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
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-- Portable Operating System Interface (POSIX), The Open Group Base
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Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
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Electrical and Electronics Engineers, Inc and The Open Group. In the
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event of any discrepancy between this version and the original IEEE and
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The Open Group Standard, the original IEEE and The Open Group Standard
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is the referee document. The original Standard can be obtained online at
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http://www.opengroup.org/unix/online.html .
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