diff options
Diffstat (limited to 'gnulib-tests/tmpfile.c')
| -rw-r--r-- | gnulib-tests/tmpfile.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/gnulib-tests/tmpfile.c b/gnulib-tests/tmpfile.c new file mode 100644 index 0000000..dd9cf82 --- /dev/null +++ b/gnulib-tests/tmpfile.c @@ -0,0 +1,187 @@ +/* Create a temporary file. + Copyright (C) 2007, 2009-2022 Free Software Foundation, Inc. + + This file is free software: you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation, either version 3 of the + License, or (at your option) any later version. + + This file 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 Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +/* Written by Ben Pfaff. */ + +#include <config.h> + +/* Specification. */ +#include <stdio.h> + +#include <errno.h> +#include <stdbool.h> + +#if defined _WIN32 && ! defined __CYGWIN__ +/* A native Windows platform. */ + +# include <fcntl.h> +# include <string.h> +# include <sys/stat.h> + +# include <io.h> + +# define WIN32_LEAN_AND_MEAN /* avoid including junk */ +# include <windows.h> + +#else + +# include <unistd.h> + +#endif + +#include "pathmax.h" +#include "tempname.h" +#include "tmpdir.h" + +/* PATH_MAX is guaranteed to be defined, because this replacement is only + used on native Windows and Android. */ + +#if defined _WIN32 && ! defined __CYGWIN__ +/* A native Windows platform. */ + +/* Don't assume that UNICODE is not defined. */ +# undef OSVERSIONINFO +# define OSVERSIONINFO OSVERSIONINFOA +# undef GetVersionEx +# define GetVersionEx GetVersionExA +# undef GetTempPath +# define GetTempPath GetTempPathA + +/* On Windows, opening a file with _O_TEMPORARY has the effect of passing + the FILE_FLAG_DELETE_ON_CLOSE flag to CreateFile(), which has the effect + of deleting the file when it is closed - even when the program crashes. + But (according to the Cygwin sources) it works only on Windows NT or newer. + So we cache the info whether we are running on Windows NT or newer. */ + +static bool +supports_delete_on_close () +{ + static int known; /* 1 = yes, -1 = no, 0 = unknown */ + if (!known) + { + OSVERSIONINFO v; + + /* According to + <https://docs.microsoft.com/en-us/windows/desktop/api/sysinfoapi/nf-sysinfoapi-getversionexa> + this structure must be initialized as follows: */ + v.dwOSVersionInfoSize = sizeof (OSVERSIONINFO); + + if (GetVersionEx (&v)) + known = (v.dwPlatformId == VER_PLATFORM_WIN32_NT ? 1 : -1); + else + known = -1; + } + return (known > 0); +} + +FILE * +tmpfile (void) +{ + char dir[PATH_MAX]; + DWORD retval; + + /* Find Windows temporary file directory. + We provide this as the directory argument to path_search because Windows + defines P_tmpdir to "\\" and will therefore try to put all temporary files + in the root directory (unless $TMPDIR is set). */ + retval = GetTempPath (PATH_MAX, dir); + if (retval > 0 && retval < PATH_MAX) + { + char xtemplate[PATH_MAX]; + + if (path_search (xtemplate, PATH_MAX, dir, NULL, true) >= 0) + { + size_t len = strlen (xtemplate); + int o_temporary = (supports_delete_on_close () ? _O_TEMPORARY : 0); + int fd; + + do + { + memcpy (&xtemplate[len - 6], "XXXXXX", 6); + if (gen_tempname (xtemplate, 0, 0, GT_NOCREATE) < 0) + { + fd = -1; + break; + } + + fd = _open (xtemplate, + _O_CREAT | _O_EXCL | o_temporary + | _O_RDWR | _O_BINARY, + _S_IREAD | _S_IWRITE); + } + while (fd < 0 && errno == EEXIST); + + if (fd >= 0) + { + FILE *fp = _fdopen (fd, "w+b"); + + if (fp != NULL) + return fp; + else + { + int saved_errno = errno; + _close (fd); + errno = saved_errno; + } + } + } + } + else + { + if (retval > 0) + errno = ENAMETOOLONG; + else + /* Ideally this should translate GetLastError () to an errno value. */ + errno = ENOENT; + } + + return NULL; +} + +#else + +FILE * +tmpfile (void) +{ + char buf[PATH_MAX]; + int fd; + FILE *fp; + + /* Try $TMPDIR first, not /tmp nor P_tmpdir, because we need this replacement + on Android, and /tmp does not exist on Android. */ + + if (path_search (buf, sizeof buf, NULL, "tmpf", true)) + return NULL; + + fd = gen_tempname (buf, 0, 0, GT_FILE); + if (fd < 0) + return NULL; + + /* Note that this relies on the Unix semantics that + a file is not really removed until it is closed. */ + (void) unlink (buf); + + if ((fp = fdopen (fd, "w+b")) == NULL) + { + int saved_errno = errno; + close (fd); + errno = saved_errno; + } + + return fp; +} + +#endif |