cosmopolitan/libc/stdio/fopen.c

76 lines
3.4 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=8 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program 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; version 2 of the License. │
│ │
│ This program 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 this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/mem/mem.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/o.h"
static const char *fixpathname(const char *pathname, int flags) {
if ((flags & O_ACCMODE) == O_RDONLY && strcmp(pathname, "-") == 0) {
return "/dev/stdin";
} else if ((flags & O_ACCMODE) == O_WRONLY && strcmp(pathname, "-") == 0) {
return "/dev/stdout";
} else {
return pathname;
}
}
static int openpathname(const char *pathname, int flags, bool *out_noclose) {
if ((flags & O_ACCMODE) == O_RDONLY && strcmp(pathname, "/dev/stdin") == 0) {
*out_noclose = true;
return fileno(stdin);
} else if ((flags & O_ACCMODE) == O_WRONLY &&
strcmp(pathname, "/dev/stdout") == 0) {
*out_noclose = true;
return fileno(stdout);
} else {
*out_noclose = false;
return open(pathname, flags, 0666);
}
}
/**
* Opens file as stream object.
*
* @param pathname is a utf-8 ideally relative filename
* @param mode is the string mode/flag DSL see fopenflags()
* @return new object to be free'd by fclose() or NULL w/ errno
* @note microsoft unilaterally deprecated this function lool
*/
FILE *fopen(const char *pathname, const char *mode) {
FILE *f;
bool noclose;
int fd, flags;
flags = fopenflags(mode);
pathname = fixpathname(pathname, flags);
if ((fd = openpathname(pathname, flags, &noclose)) != -1) {
if ((f = fdopen(fd, mode)) != NULL) {
f->noclose = noclose;
return f;
} else {
if (!noclose) close(fd);
return NULL;
}
} else {
return NULL;
}
}