/contrib/groff/src/libs/libgroff/tmpfile.cpp
https://bitbucket.org/freebsd/freebsd-head/ · C++ · 190 lines · 124 code · 18 blank · 48 comment · 22 complexity · dc2a2a7163033cdbbac1fa1e91d3d3b5 MD5 · raw file
- // -*- C++ -*-
- /* Copyright (C) 1989, 1990, 1991, 1992, 2000, 2001, 2003
- Free Software Foundation, Inc.
- Written by James Clark (jjc@jclark.com)
- This file is part of groff.
- groff is free software; you can redistribute it and/or modify it under
- the terms of the GNU General Public License as published by the Free
- Software Foundation; either version 2, or (at your option) any later
- version.
- groff is distributed in the hope that it will be useful, but WITHOUT ANY
- WARRANTY; without even the implied warranty of MERCHANTABILITY or
- FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- for more details.
- You should have received a copy of the GNU General Public License along
- with groff; see the file COPYING. If not, write to the Free Software
- Foundation, 51 Franklin St - Fifth Floor, Boston, MA 02110-1301, USA. */
- #include "lib.h"
- #include <errno.h>
- #include <stdlib.h>
- #include "posix.h"
- #include "errarg.h"
- #include "error.h"
- #include "nonposix.h"
- // If this is set, create temporary files there
- #define GROFF_TMPDIR_ENVVAR "GROFF_TMPDIR"
- // otherwise if this is set, create temporary files there
- #define TMPDIR_ENVVAR "TMPDIR"
- // otherwise, on MS-DOS or MS-Windows ...
- #if defined(__MSDOS__) || defined(_WIN32)
- // if either of these is set, create temporary files there
- // (giving priority to WIN32_TMPDIR_ENVVAR)
- #define WIN32_TMPDIR_ENVVAR "TMP"
- #define MSDOS_TMPDIR_ENVVAR "TEMP"
- #endif
- // otherwise if P_tmpdir is defined, create temporary files there
- #ifdef P_tmpdir
- # define DEFAULT_TMPDIR P_tmpdir
- #else
- // otherwise create temporary files here.
- # define DEFAULT_TMPDIR "/tmp"
- #endif
- // Use this as the prefix for temporary filenames.
- #define TMPFILE_PREFIX_SHORT ""
- #define TMPFILE_PREFIX_LONG "groff"
- char *tmpfile_prefix;
- size_t tmpfile_prefix_len;
- int use_short_postfix = 0;
- struct temp_init {
- temp_init();
- ~temp_init();
- } _temp_init;
- temp_init::temp_init()
- {
- // First, choose a location for creating temporary files...
- const char *tem;
- // using the first match for any of the environment specs in listed order.
- if (
- (tem = getenv(GROFF_TMPDIR_ENVVAR)) == NULL
- && (tem = getenv(TMPDIR_ENVVAR)) == NULL
- #if defined(__MSDOS__) || defined(_WIN32)
- // If we didn't find a match for either of the above
- // (which are preferred, regardless of the host operating system),
- // and we are hosted on either MS-Windows or MS-DOS,
- // then try the Microsoft conventions.
- && (tem = getenv(WIN32_TMPDIR_ENVVAR)) == NULL
- && (tem = getenv(MSDOS_TMPDIR_ENVVAR)) == NULL
- #endif
- )
- // If we didn't find an environment spec fall back to this default.
- tem = DEFAULT_TMPDIR;
- size_t tem_len = strlen(tem);
- const char *tem_end = tem + tem_len - 1;
- int need_slash = strchr(DIR_SEPS, *tem_end) == NULL ? 1 : 0;
- char *tem2 = new char[tem_len + need_slash + 1];
- strcpy(tem2, tem);
- if (need_slash)
- strcat(tem2, "/");
- const char *tem3 = TMPFILE_PREFIX_LONG;
- if (file_name_max(tem2) <= 14) {
- tem3 = TMPFILE_PREFIX_SHORT;
- use_short_postfix = 1;
- }
- tmpfile_prefix_len = tem_len + need_slash + strlen(tem3);
- tmpfile_prefix = new char[tmpfile_prefix_len + 1];
- strcpy(tmpfile_prefix, tem2);
- strcat(tmpfile_prefix, tem3);
- a_delete tem2;
- }
- temp_init::~temp_init()
- {
- a_delete tmpfile_prefix;
- }
- /*
- * Generate a temporary name template with a postfix
- * immediately after the TMPFILE_PREFIX.
- * It uses the groff preferences for a temporary directory.
- * Note that no file name is either created or opened,
- * only the *template* is returned.
- */
- char *xtmptemplate(const char *postfix_long, const char *postfix_short)
- {
- const char *postfix = use_short_postfix ? postfix_short : postfix_long;
- int postlen = 0;
- if (postfix)
- postlen = strlen(postfix);
- char *templ = new char[tmpfile_prefix_len + postlen + 6 + 1];
- strcpy(templ, tmpfile_prefix);
- if (postlen > 0)
- strcat(templ, postfix);
- strcat(templ, "XXXXXX");
- return templ;
- }
- // The trick with unlinking the temporary file while it is still in
- // use is not portable, it will fail on MS-DOS and most MS-Windows
- // filesystems. So it cannot be used on non-Posix systems.
- // Instead, we maintain a list of files to be deleted on exit.
- // This should be portable to all platforms.
- struct xtmpfile_list {
- char *fname;
- xtmpfile_list *next;
- xtmpfile_list(char *fn) : fname(fn), next(0) {}
- };
- xtmpfile_list *xtmpfiles_to_delete = 0;
- struct xtmpfile_list_init {
- ~xtmpfile_list_init();
- } _xtmpfile_list_init;
- xtmpfile_list_init::~xtmpfile_list_init()
- {
- xtmpfile_list *x = xtmpfiles_to_delete;
- while (x != 0) {
- if (unlink(x->fname) < 0)
- error("cannot unlink `%1': %2", x->fname, strerror(errno));
- xtmpfile_list *tmp = x;
- x = x->next;
- a_delete tmp->fname;
- delete tmp;
- }
- }
- static void add_tmp_file(const char *name)
- {
- char *s = new char[strlen(name)+1];
- strcpy(s, name);
- xtmpfile_list *x = new xtmpfile_list(s);
- x->next = xtmpfiles_to_delete;
- xtmpfiles_to_delete = x;
- }
- // Open a temporary file and with fatal error on failure.
- FILE *xtmpfile(char **namep,
- const char *postfix_long, const char *postfix_short,
- int do_unlink)
- {
- char *templ = xtmptemplate(postfix_long, postfix_short);
- errno = 0;
- int fd = mkstemp(templ);
- if (fd < 0)
- fatal("cannot create temporary file: %1", strerror(errno));
- errno = 0;
- FILE *fp = fdopen(fd, FOPEN_RWB); // many callers of xtmpfile use binary I/O
- if (!fp)
- fatal("fdopen: %1", strerror(errno));
- if (do_unlink)
- add_tmp_file(templ);
- if (namep)
- *namep = templ;
- else
- a_delete templ;
- return fp;
- }