mirror of https://github.com/mkerrisk/man-pages
87 lines
2.6 KiB
Plaintext
87 lines
2.6 KiB
Plaintext
.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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.TH "MKSTEMP" 3P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
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.\" mkstemp
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.SH NAME
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mkstemp \- make a unique filename
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.SH SYNOPSIS
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.LP
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\fB#include <stdlib.h>
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.br
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.sp
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int mkstemp(char *\fP\fItemplate\fP\fB); \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 \fImkstemp\fP() function shall replace the contents of the string
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pointed to by \fItemplate\fP by a unique filename, and
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return a file descriptor for the file open for reading and writing.
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The function thus prevents any possible race condition between
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testing whether the file exists and opening it for use. The string
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in \fItemplate\fP should look like a filename with six trailing
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\fB'X'\fP s; \fImkstemp\fP() replaces each \fB'X'\fP with a character
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from the portable filename character set. The
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characters are chosen such that the resulting name does not duplicate
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the name of an existing file at the time of a call to
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\fImkstemp\fP().
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.SH RETURN VALUE
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.LP
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Upon successful completion, \fImkstemp\fP() shall return an open file
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descriptor. Otherwise, -1 shall be returned if no
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suitable file could be created.
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.SH ERRORS
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.LP
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No errors are defined.
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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 Filename
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.LP
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The following example creates a file with a 10-character name beginning
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with the characters \fB"file"\fP and opens the file
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for reading and writing. The value returned as the value of \fIfd\fP
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is a file descriptor that identifies the file.
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.sp
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.RS
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.nf
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\fB#include <stdlib.h>
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\&...
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char template[] = "/tmp/fileXXXXXX";
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int fd;
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.sp
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fd = mkstemp(template);
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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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It is possible to run out of letters.
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.LP
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The \fImkstemp\fP() function need not check to determine whether the
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filename part of \fItemplate\fP exceeds the maximum
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allowable filename length.
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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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\fIgetpid\fP() , \fIopen\fP() , \fItmpfile\fP()
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, \fItmpnam\fP() , the Base Definitions volume of IEEE\ Std\ 1003.1-2001,
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\fI<stdlib.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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