mirror of
https://github.com/jart/cosmopolitan.git
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103 lines
4.1 KiB
C
103 lines
4.1 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/bits/safemacros.internal.h"
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#include "libc/calls/calls.h"
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#include "libc/runtime/runtime.h"
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#include "libc/str/str.h"
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#include "libc/sysv/errfuns.h"
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static bool AccessCommand(char path[hasatleast PATH_MAX], const char *name,
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size_t namelen, size_t pathlen) {
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if (pathlen + 1 + namelen + 1 + 4 + 1 > PATH_MAX) return -1;
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if (pathlen && (path[pathlen - 1] != '/' && path[pathlen - 1] != '\\')) {
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path[pathlen] =
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!IsWindows() ? '/' : memchr(path, '\\', pathlen) ? '\\' : '/';
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pathlen++;
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}
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memcpy(path + pathlen, name, namelen + 1);
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if (isexecutable(path)) return true;
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memcpy(path + pathlen + namelen, ".com", 5);
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if (isexecutable(path)) return true;
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memcpy(path + pathlen + namelen, ".exe", 5);
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if (isexecutable(path)) return true;
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return false;
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}
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static bool SearchPath(char path[hasatleast PATH_MAX], const char *name,
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size_t namelen) {
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size_t i;
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const char *p;
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p = firstnonnull(emptytonull(getenv("PATH")), "/bin:/usr/local/bin:/usr/bin");
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for (;;) {
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for (i = 0; p[i] && p[i] != ':' && p[i] != ';'; ++i) {
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if (i < PATH_MAX) path[i] = p[i];
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}
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if (AccessCommand(path, name, namelen, i)) {
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return true;
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}
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if (p[i] == ':' || p[i] == ';') {
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p += i + 1;
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} else {
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break;
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}
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}
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return false;
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}
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/**
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* Resolves full pathname of executable.
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*
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* @return execve()'able path, or NULL w/ errno
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* @errno ENOENT, EACCES, ENOMEM
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* @see free(), execvpe()
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* @asyncsignalsafe
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* @vforksafe
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*/
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char *commandv(const char *name, char pathbuf[hasatleast PATH_MAX]) {
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char *p;
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size_t namelen;
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int rc, olderr;
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if (!(namelen = strlen(name))) {
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enoent();
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return NULL;
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}
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if (namelen + 1 > PATH_MAX) {
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enametoolong();
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return NULL;
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}
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if (strchr(name, '/') || strchr(name, '\\')) {
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if (AccessCommand(strcpy(pathbuf, ""), name, namelen, 0)) {
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return pathbuf;
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} else {
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return NULL;
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}
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}
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olderr = errno;
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if ((IsWindows() &&
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(AccessCommand(pathbuf, name, namelen,
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stpcpy(pathbuf, kNtSystemDirectory) - pathbuf) ||
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AccessCommand(pathbuf, name, namelen,
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stpcpy(pathbuf, kNtWindowsDirectory) - pathbuf))) ||
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SearchPath(pathbuf, name, namelen)) {
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errno = olderr;
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return pathbuf;
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} else {
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return NULL;
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}
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}
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