mpv/osdep/io.c

821 lines
22 KiB
C

/*
* unicode/utf-8 I/O helpers and wrappers for Windows
*
* Contains parts based on libav code (http://libav.org).
*
* This file is part of mpv.
*
* mpv 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 2.1 of the License, or (at your option) any later version.
*
* mpv 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 mpv. If not, see <http://www.gnu.org/licenses/>.
*/
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <limits.h>
#include <unistd.h>
#include "mpv_talloc.h"
#include "config.h"
#include "misc/random.h"
#include "osdep/io.h"
#include "osdep/terminal.h"
#if HAVE_UWP
// Missing from MinGW headers.
#include <windows.h>
WINBASEAPI UINT WINAPI GetTempFileNameW(LPCWSTR lpPathName, LPCWSTR lpPrefixString,
UINT uUnique, LPWSTR lpTempFileName);
WINBASEAPI DWORD WINAPI GetCurrentDirectoryW(DWORD nBufferLength, LPWSTR lpBuffer);
WINBASEAPI DWORD WINAPI GetFullPathNameW(LPCWSTR lpFileName, DWORD nBufferLength,
LPWSTR lpBuffer, LPWSTR *lpFilePart);
#endif
// Set the CLOEXEC flag on the given fd.
// On error, false is returned (and errno set).
bool mp_set_cloexec(int fd)
{
#if defined(F_SETFD)
if (fd >= 0) {
int flags = fcntl(fd, F_GETFD);
if (flags == -1)
return false;
if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) == -1)
return false;
}
#endif
return true;
}
#ifdef __MINGW32__
int mp_make_cloexec_pipe(int pipes[2])
{
pipes[0] = pipes[1] = -1;
return -1;
}
#else
int mp_make_cloexec_pipe(int pipes[2])
{
if (pipe(pipes) != 0) {
pipes[0] = pipes[1] = -1;
return -1;
}
for (int i = 0; i < 2; i++)
mp_set_cloexec(pipes[i]);
return 0;
}
#endif
#ifdef __MINGW32__
int mp_make_wakeup_pipe(int pipes[2])
{
return mp_make_cloexec_pipe(pipes);
}
#else
// create a pipe, and set it to non-blocking (and also set FD_CLOEXEC)
int mp_make_wakeup_pipe(int pipes[2])
{
if (mp_make_cloexec_pipe(pipes) < 0)
return -1;
for (int i = 0; i < 2; i++) {
int val = fcntl(pipes[i], F_GETFL) | O_NONBLOCK;
fcntl(pipes[i], F_SETFL, val);
}
return 0;
}
#endif
void mp_flush_wakeup_pipe(int pipe_end)
{
#ifndef __MINGW32__
char buf[100];
(void)read(pipe_end, buf, sizeof(buf));
#endif
}
#ifdef _WIN32
#include <windows.h>
#include <wchar.h>
#include <stdio.h>
#include <stddef.h>
//copied and modified from libav
//http://git.libav.org/?p=libav.git;a=blob;f=libavformat/os_support.c;h=a0fcd6c9ba2be4b0dbcc476f6c53587345cc1152;hb=HEADl30
wchar_t *mp_from_utf8(void *talloc_ctx, const char *s)
{
int count = MultiByteToWideChar(CP_UTF8, 0, s, -1, NULL, 0);
if (count <= 0)
abort();
wchar_t *ret = talloc_array(talloc_ctx, wchar_t, count);
MultiByteToWideChar(CP_UTF8, 0, s, -1, ret, count);
return ret;
}
char *mp_to_utf8(void *talloc_ctx, const wchar_t *s)
{
int count = WideCharToMultiByte(CP_UTF8, 0, s, -1, NULL, 0, NULL, NULL);
if (count <= 0)
abort();
char *ret = talloc_array(talloc_ctx, char, count);
WideCharToMultiByte(CP_UTF8, 0, s, -1, ret, count, NULL, NULL);
return ret;
}
#endif // _WIN32
#ifdef __MINGW32__
#include <io.h>
#include <fcntl.h>
#include <pthread.h>
static void set_errno_from_lasterror(void)
{
// This just handles the error codes expected from CreateFile at the moment
switch (GetLastError()) {
case ERROR_FILE_NOT_FOUND:
errno = ENOENT;
break;
case ERROR_SHARING_VIOLATION:
case ERROR_ACCESS_DENIED:
errno = EACCES;
break;
case ERROR_FILE_EXISTS:
case ERROR_ALREADY_EXISTS:
errno = EEXIST;
break;
case ERROR_PIPE_BUSY:
errno = EAGAIN;
break;
default:
errno = EINVAL;
break;
}
}
static time_t filetime_to_unix_time(int64_t wintime)
{
static const int64_t hns_per_second = 10000000ll;
static const int64_t win_to_unix_epoch = 11644473600ll;
return wintime / hns_per_second - win_to_unix_epoch;
}
static bool get_file_ids_win8(HANDLE h, dev_t *dev, ino_t *ino)
{
FILE_ID_INFO ii;
if (!GetFileInformationByHandleEx(h, FileIdInfo, &ii, sizeof(ii)))
return false;
*dev = ii.VolumeSerialNumber;
// The definition of FILE_ID_128 differs between mingw-w64 and the Windows
// SDK, but we can ignore that by just memcpying it. This will also
// truncate the file ID on 32-bit Windows, which doesn't support __int128.
// 128-bit file IDs are only used for ReFS, so that should be okay.
assert(sizeof(*ino) <= sizeof(ii.FileId));
memcpy(ino, &ii.FileId, sizeof(*ino));
return true;
}
#if HAVE_UWP
static bool get_file_ids(HANDLE h, dev_t *dev, ino_t *ino)
{
return false;
}
#else
static bool get_file_ids(HANDLE h, dev_t *dev, ino_t *ino)
{
// GetFileInformationByHandle works on FAT partitions and Windows 7, but
// doesn't work in UWP and can produce non-unique IDs on ReFS
BY_HANDLE_FILE_INFORMATION bhfi;
if (!GetFileInformationByHandle(h, &bhfi))
return false;
*dev = bhfi.dwVolumeSerialNumber;
*ino = ((ino_t)bhfi.nFileIndexHigh << 32) | bhfi.nFileIndexLow;
return true;
}
#endif
// Like fstat(), but with a Windows HANDLE
static int hstat(HANDLE h, struct mp_stat *buf)
{
// Handle special (or unknown) file types first
switch (GetFileType(h) & ~FILE_TYPE_REMOTE) {
case FILE_TYPE_PIPE:
*buf = (struct mp_stat){ .st_nlink = 1, .st_mode = _S_IFIFO | 0644 };
return 0;
case FILE_TYPE_CHAR: // character device
*buf = (struct mp_stat){ .st_nlink = 1, .st_mode = _S_IFCHR | 0644 };
return 0;
case FILE_TYPE_UNKNOWN:
errno = EBADF;
return -1;
}
struct mp_stat st = { 0 };
FILE_BASIC_INFO bi;
if (!GetFileInformationByHandleEx(h, FileBasicInfo, &bi, sizeof(bi))) {
errno = EBADF;
return -1;
}
st.st_atime = filetime_to_unix_time(bi.LastAccessTime.QuadPart);
st.st_mtime = filetime_to_unix_time(bi.LastWriteTime.QuadPart);
st.st_ctime = filetime_to_unix_time(bi.ChangeTime.QuadPart);
FILE_STANDARD_INFO si;
if (!GetFileInformationByHandleEx(h, FileStandardInfo, &si, sizeof(si))) {
errno = EBADF;
return -1;
}
st.st_nlink = si.NumberOfLinks;
// Here we pretend Windows has POSIX permissions by pretending all
// directories are 755 and regular files are 644
if (si.Directory) {
st.st_mode |= _S_IFDIR | 0755;
} else {
st.st_mode |= _S_IFREG | 0644;
st.st_size = si.EndOfFile.QuadPart;
}
if (!get_file_ids_win8(h, &st.st_dev, &st.st_ino)) {
// Fall back to the Windows 7 method (also used for FAT in Win8)
if (!get_file_ids(h, &st.st_dev, &st.st_ino)) {
errno = EBADF;
return -1;
}
}
*buf = st;
return 0;
}
int mp_stat(const char *path, struct mp_stat *buf)
{
wchar_t *wpath = mp_from_utf8(NULL, path);
HANDLE h = CreateFileW(wpath, FILE_READ_ATTRIBUTES,
FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS | SECURITY_SQOS_PRESENT |
SECURITY_IDENTIFICATION, NULL);
talloc_free(wpath);
if (h == INVALID_HANDLE_VALUE) {
set_errno_from_lasterror();
return -1;
}
int ret = hstat(h, buf);
CloseHandle(h);
return ret;
}
int mp_fstat(int fd, struct mp_stat *buf)
{
HANDLE h = (HANDLE)_get_osfhandle(fd);
if (h == INVALID_HANDLE_VALUE) {
errno = EBADF;
return -1;
}
// Use mpv's hstat() function rather than MSVCRT's fstat() because mpv's
// supports directories and device/inode numbers.
return hstat(h, buf);
}
#if HAVE_UWP
static int mp_vfprintf(FILE *stream, const char *format, va_list args)
{
return vfprintf(stream, format, args);
}
#else
static int mp_check_console(HANDLE wstream)
{
if (wstream != INVALID_HANDLE_VALUE) {
unsigned int filetype = GetFileType(wstream);
if (!((filetype == FILE_TYPE_UNKNOWN) &&
(GetLastError() != ERROR_SUCCESS)))
{
filetype &= ~(FILE_TYPE_REMOTE);
if (filetype == FILE_TYPE_CHAR) {
DWORD ConsoleMode;
int ret = GetConsoleMode(wstream, &ConsoleMode);
if (!(!ret && (GetLastError() == ERROR_INVALID_HANDLE))) {
// This seems to be a console
return 1;
}
}
}
}
return 0;
}
static int mp_vfprintf(FILE *stream, const char *format, va_list args)
{
int done = 0;
HANDLE wstream = INVALID_HANDLE_VALUE;
if (stream == stdout || stream == stderr) {
wstream = GetStdHandle(stream == stdout ?
STD_OUTPUT_HANDLE : STD_ERROR_HANDLE);
}
if (mp_check_console(wstream)) {
size_t len = vsnprintf(NULL, 0, format, args) + 1;
char *buf = talloc_array(NULL, char, len);
if (buf) {
done = vsnprintf(buf, len, format, args);
mp_write_console_ansi(wstream, buf);
}
talloc_free(buf);
} else {
done = vfprintf(stream, format, args);
}
return done;
}
#endif
int mp_fprintf(FILE *stream, const char *format, ...)
{
int res;
va_list args;
va_start(args, format);
res = mp_vfprintf(stream, format, args);
va_end(args);
return res;
}
int mp_printf(const char *format, ...)
{
int res;
va_list args;
va_start(args, format);
res = mp_vfprintf(stdout, format, args);
va_end(args);
return res;
}
int mp_open(const char *filename, int oflag, ...)
{
// Always use all share modes, which is useful for opening files that are
// open in other processes, and also more POSIX-like
static const DWORD share =
FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE;
// Setting FILE_APPEND_DATA and avoiding GENERIC_WRITE/FILE_WRITE_DATA
// will make the file handle use atomic append behavior
static const DWORD append =
FILE_APPEND_DATA | FILE_WRITE_ATTRIBUTES | FILE_WRITE_EA;
DWORD access = 0;
DWORD disposition = 0;
DWORD flags = 0;
switch (oflag & (_O_RDONLY | _O_RDWR | _O_WRONLY | _O_APPEND)) {
case _O_RDONLY:
access = GENERIC_READ;
flags |= FILE_FLAG_BACKUP_SEMANTICS; // For opening directories
break;
case _O_RDWR:
access = GENERIC_READ | GENERIC_WRITE;
break;
case _O_RDWR | _O_APPEND:
case _O_RDONLY | _O_APPEND:
access = GENERIC_READ | append;
break;
case _O_WRONLY:
access = GENERIC_WRITE;
break;
case _O_WRONLY | _O_APPEND:
access = append;
break;
default:
errno = EINVAL;
return -1;
}
switch (oflag & (_O_CREAT | _O_EXCL | _O_TRUNC)) {
case 0:
case _O_EXCL: // Like MSVCRT, ignore invalid use of _O_EXCL
disposition = OPEN_EXISTING;
break;
case _O_TRUNC:
case _O_TRUNC | _O_EXCL:
disposition = TRUNCATE_EXISTING;
break;
case _O_CREAT:
disposition = OPEN_ALWAYS;
flags |= FILE_ATTRIBUTE_NORMAL;
break;
case _O_CREAT | _O_TRUNC:
disposition = CREATE_ALWAYS;
break;
case _O_CREAT | _O_EXCL:
case _O_CREAT | _O_EXCL | _O_TRUNC:
disposition = CREATE_NEW;
flags |= FILE_ATTRIBUTE_NORMAL;
break;
}
// Opening a named pipe as a file can allow the pipe server to impersonate
// mpv's process, which could be a security issue. Set SQOS flags, so pipe
// servers can only identify the mpv process, not impersonate it.
if (disposition != CREATE_NEW)
flags |= SECURITY_SQOS_PRESENT | SECURITY_IDENTIFICATION;
// Keep the same semantics for some MSVCRT-specific flags
if (oflag & _O_TEMPORARY) {
flags |= FILE_FLAG_DELETE_ON_CLOSE;
access |= DELETE;
}
if (oflag & _O_SHORT_LIVED)
flags |= FILE_ATTRIBUTE_TEMPORARY;
if (oflag & _O_SEQUENTIAL) {
flags |= FILE_FLAG_SEQUENTIAL_SCAN;
} else if (oflag & _O_RANDOM) {
flags |= FILE_FLAG_RANDOM_ACCESS;
}
// Open the Windows file handle
wchar_t *wpath = mp_from_utf8(NULL, filename);
HANDLE h = CreateFileW(wpath, access, share, NULL, disposition, flags, NULL);
talloc_free(wpath);
if (h == INVALID_HANDLE_VALUE) {
set_errno_from_lasterror();
return -1;
}
// Map the Windows file handle to a CRT file descriptor. Note: MSVCRT only
// cares about the following oflags.
oflag &= _O_APPEND | _O_RDONLY | _O_RDWR | _O_WRONLY;
oflag |= _O_NOINHERIT; // We never create inheritable handles
int fd = _open_osfhandle((intptr_t)h, oflag);
if (fd < 0) {
CloseHandle(h);
return -1;
}
return fd;
}
int mp_creat(const char *filename, int mode)
{
return mp_open(filename, _O_CREAT | _O_WRONLY | _O_TRUNC, mode);
}
FILE *mp_fopen(const char *filename, const char *mode)
{
if (!mode[0]) {
errno = EINVAL;
return NULL;
}
int rwmode;
int oflags = 0;
switch (mode[0]) {
case 'r':
rwmode = _O_RDONLY;
break;
case 'w':
rwmode = _O_WRONLY;
oflags |= _O_CREAT | _O_TRUNC;
break;
case 'a':
rwmode = _O_WRONLY;
oflags |= _O_CREAT | _O_APPEND;
break;
default:
errno = EINVAL;
return NULL;
}
// Parse extra mode flags
for (const char *pos = mode + 1; *pos; pos++) {
switch (*pos) {
case '+': rwmode = _O_RDWR; break;
case 'x': oflags |= _O_EXCL; break;
// Ignore unknown flags (glibc does too)
default: break;
}
}
// Open a CRT file descriptor
int fd = mp_open(filename, rwmode | oflags);
if (fd < 0)
return NULL;
// Add 'b' to the mode so the CRT knows the file is opened in binary mode
char bmode[] = { mode[0], 'b', rwmode == _O_RDWR ? '+' : '\0', '\0' };
FILE *fp = fdopen(fd, bmode);
if (!fp) {
close(fd);
return NULL;
}
return fp;
}
// Windows' MAX_PATH/PATH_MAX/FILENAME_MAX is fixed to 260, but this limit
// applies to unicode paths encoded with wchar_t (2 bytes on Windows). The UTF-8
// version could end up bigger in memory. In the worst case each wchar_t is
// encoded to 3 bytes in UTF-8, so in the worst case we have:
// wcslen(wpath) * 3 <= strlen(utf8path)
// Thus we need MP_PATH_MAX as the UTF-8/char version of PATH_MAX.
// Also make sure there's free space for the terminating \0.
// (For codepoints encoded as UTF-16 surrogate pairs, UTF-8 has the same length.)
#define MP_PATH_MAX (FILENAME_MAX * 3 + 1)
struct mp_dir {
DIR crap; // must be first member
_WDIR *wdir;
union {
struct dirent dirent;
// dirent has space only for FILENAME_MAX bytes. _wdirent has space for
// FILENAME_MAX wchar_t, which might end up bigger as UTF-8 in some
// cases. Guarantee we can always hold _wdirent.d_name converted to
// UTF-8 (see MP_PATH_MAX).
// This works because dirent.d_name is the last member of dirent.
char space[MP_PATH_MAX];
};
};
DIR* mp_opendir(const char *path)
{
wchar_t *wpath = mp_from_utf8(NULL, path);
_WDIR *wdir = _wopendir(wpath);
talloc_free(wpath);
if (!wdir)
return NULL;
struct mp_dir *mpdir = talloc(NULL, struct mp_dir);
// DIR is supposed to be opaque, but unfortunately the MinGW headers still
// define it. Make sure nobody tries to use it.
memset(&mpdir->crap, 0xCD, sizeof(mpdir->crap));
mpdir->wdir = wdir;
return (DIR*)mpdir;
}
struct dirent* mp_readdir(DIR *dir)
{
struct mp_dir *mpdir = (struct mp_dir*)dir;
struct _wdirent *wdirent = _wreaddir(mpdir->wdir);
if (!wdirent)
return NULL;
size_t buffersize = sizeof(mpdir->space) - offsetof(struct dirent, d_name);
WideCharToMultiByte(CP_UTF8, 0, wdirent->d_name, -1, mpdir->dirent.d_name,
buffersize, NULL, NULL);
mpdir->dirent.d_ino = 0;
mpdir->dirent.d_reclen = 0;
mpdir->dirent.d_namlen = strlen(mpdir->dirent.d_name);
return &mpdir->dirent;
}
int mp_closedir(DIR *dir)
{
struct mp_dir *mpdir = (struct mp_dir*)dir;
int res = _wclosedir(mpdir->wdir);
talloc_free(mpdir);
return res;
}
int mp_mkdir(const char *path, int mode)
{
wchar_t *wpath = mp_from_utf8(NULL, path);
int res = _wmkdir(wpath);
talloc_free(wpath);
return res;
}
char *mp_win32_getcwd(char *buf, size_t size)
{
if (size >= SIZE_MAX / 3 - 1) {
errno = ENOMEM;
return NULL;
}
size_t wbuffer = size * 3 + 1;
wchar_t *wres = talloc_array(NULL, wchar_t, wbuffer);
DWORD wlen = GetFullPathNameW(L".", wbuffer, wres, NULL);
if (wlen >= wbuffer || wlen == 0) {
talloc_free(wres);
errno = wlen ? ERANGE : ENOENT;
return NULL;
}
char *t = mp_to_utf8(NULL, wres);
talloc_free(wres);
size_t st = strlen(t);
if (st >= size) {
talloc_free(t);
errno = ERANGE;
return NULL;
}
memcpy(buf, t, st + 1);
talloc_free(t);
return buf;
}
static char **utf8_environ;
static void *utf8_environ_ctx;
static void free_env(void)
{
talloc_free(utf8_environ_ctx);
utf8_environ_ctx = NULL;
utf8_environ = NULL;
}
// Note: UNIX getenv() returns static strings, and we try to do the same. Since
// using putenv() is not multithreading safe, we don't expect env vars to change
// at runtime, and converting/allocating them in advance is ok.
static void init_getenv(void)
{
#if !HAVE_UWP
wchar_t *wenv = GetEnvironmentStringsW();
if (!wenv)
return;
utf8_environ_ctx = talloc_new(NULL);
int num_env = 0;
while (1) {
size_t len = wcslen(wenv);
if (!len)
break;
char *s = mp_to_utf8(utf8_environ_ctx, wenv);
MP_TARRAY_APPEND(utf8_environ_ctx, utf8_environ, num_env, s);
wenv += len + 1;
}
MP_TARRAY_APPEND(utf8_environ_ctx, utf8_environ, num_env, NULL);
// Avoid showing up in leak detectors etc.
atexit(free_env);
#endif
}
char *mp_getenv(const char *name)
{
static pthread_once_t once_init_getenv = PTHREAD_ONCE_INIT;
pthread_once(&once_init_getenv, init_getenv);
// Copied from musl, http://git.musl-libc.org/cgit/musl/tree/COPYRIGHT
// Copyright © 2005-2013 Rich Felker, standard MIT license
int i;
size_t l = strlen(name);
if (!utf8_environ || !*name || strchr(name, '=')) return NULL;
for (i=0; utf8_environ[i] && (strncmp(name, utf8_environ[i], l)
|| utf8_environ[i][l] != '='); i++) {}
if (utf8_environ[i]) return utf8_environ[i] + l+1;
return NULL;
}
char ***mp_penviron()
{
mp_getenv(""); // ensure init
return &utf8_environ; // `environ' should be an l-value
}
off_t mp_lseek(int fd, off_t offset, int whence)
{
HANDLE h = (HANDLE)_get_osfhandle(fd);
if (h != INVALID_HANDLE_VALUE && GetFileType(h) != FILE_TYPE_DISK) {
errno = ESPIPE;
return (off_t)-1;
}
return _lseeki64(fd, offset, whence);
}
#if HAVE_UWP
void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset)
{
errno = ENOSYS;
return MAP_FAILED;
}
int munmap(void *addr, size_t length)
{
errno = ENOSYS;
return -1;
}
int msync(void *addr, size_t length, int flags)
{
errno = ENOSYS;
return -1;
}
#else
// Limited mmap() wrapper, inspired by:
// http://code.google.com/p/mman-win32/source/browse/trunk/mman.c
void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset)
{
assert(addr == NULL); // not implemented
assert(flags == MAP_SHARED); // not implemented
HANDLE osf = (HANDLE)_get_osfhandle(fd);
if (!osf) {
errno = EBADF;
return MAP_FAILED;
}
DWORD protect = 0;
DWORD access = 0;
if (prot & PROT_WRITE) {
protect = PAGE_READWRITE;
access = FILE_MAP_WRITE;
} else if (prot & PROT_READ) {
protect = PAGE_READONLY;
access = FILE_MAP_READ;
}
DWORD l_low = (uint32_t)length;
DWORD l_high = ((uint64_t)length) >> 32;
HANDLE map = CreateFileMapping(osf, NULL, protect, l_high, l_low, NULL);
if (!map) {
errno = EACCES; // something random
return MAP_FAILED;
}
DWORD o_low = (uint32_t)offset;
DWORD o_high = ((uint64_t)offset) >> 32;
void *p = MapViewOfFile(map, access, o_high, o_low, length);
CloseHandle(map);
if (!p) {
errno = EINVAL;
return MAP_FAILED;
}
return p;
}
int munmap(void *addr, size_t length)
{
UnmapViewOfFile(addr);
return 0;
}
int msync(void *addr, size_t length, int flags)
{
FlushViewOfFile(addr, length);
return 0;
}
#endif
locale_t newlocale(int category, const char *locale, locale_t base)
{
return (locale_t)1;
}
locale_t uselocale(locale_t locobj)
{
return (locale_t)1;
}
void freelocale(locale_t locobj)
{
}
#endif // __MINGW32__
int mp_mkostemps(char *template, int suffixlen, int flags)
{
size_t len = strlen(template);
char *t = len >= 6 + suffixlen ? &template[len - (6 + suffixlen)] : NULL;
if (!t || strncmp(t, "XXXXXX", 6) != 0) {
errno = EINVAL;
return -1;
}
for (size_t fuckshit = 0; fuckshit < UINT32_MAX; fuckshit++) {
// Using a random value may make it require fewer iterations (even if
// not truly random; just a counter would be sufficient).
size_t fuckmess = mp_rand_next();
char crap[7] = "";
snprintf(crap, sizeof(crap), "%06zx", fuckmess);
memcpy(t, crap, 6);
int res = open(template, O_RDWR | O_CREAT | O_EXCL | flags, 0600);
if (res >= 0 || errno != EEXIST)
return res;
}
errno = EEXIST;
return -1;
}