cosmopolitan/libc/calls/ischardev.c

47 lines
2.5 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 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/calls/internal.h"
#include "libc/calls/struct/stat.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/nt/enum/filetype.h"
#include "libc/nt/files.h"
/**
* Returns true if file descriptor is backed by character i/o.
*/
textstartup bool32 ischardev(int fd) {
int olderr;
struct stat st;
if (!IsWindows()) {
olderr = errno;
if (fstat$sysv(fd, &st) != -1) {
return S_ISCHR(st.st_mode);
} else {
errno = olderr;
return false;
}
} else {
return __isfdkind(fd, kFdFile) &&
GetFileType(g_fds.p[fd].handle) == kNtFileTypeChar;
}
}