cosmopolitan/libc/calls/commandv.c

124 lines
5.0 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/bits/progn.internal.h"
#include "libc/bits/safemacros.internal.h"
#include "libc/calls/calls.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/fmt/conv.h"
#include "libc/nt/ntdll.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/ok.h"
#include "libc/sysv/errfuns.h"
static int accessexe(char pathname[hasatleast PATH_MAX], size_t len,
const char *ext) {
len = stpcpy(&pathname[len], ext) - &pathname[0];
if (isexecutable(pathname)) {
return len;
} else {
return -1;
}
}
static int accesscmd(char pathname[hasatleast PATH_MAX], const char *path,
const char *name, size_t namelen) { /* cf. %PATHEXT% */
int rc;
char *p;
bool hasdot;
size_t pathlen, len;
pathlen = strlen(path);
if (pathlen + 1 + namelen + 1 + 4 + 1 > PATH_MAX) return -1;
p = mempcpy(pathname, path, pathlen);
if (pathlen && pathname[pathlen - 1] != '/') *p++ = '/';
p = mempcpy(p, name, namelen);
len = p - &pathname[0];
hasdot = !!memchr(basename(name), '.', namelen);
if ((hasdot && (rc = accessexe(pathname, len, "")) != -1) ||
(!hasdot &&
((rc = accessexe(pathname, len, ".com")) != -1 ||
(IsWindows() && (rc = accessexe(pathname, len, ".exe")) != -1) ||
(!IsWindows() && (rc = accessexe(pathname, len, "")) != -1)))) {
return rc;
} else {
return -1;
}
}
static int searchcmdpath(char pathname[hasatleast PATH_MAX], const char *name,
size_t namelen) {
int rc;
char *path, *pathtok, ep[PATH_MAX];
rc = -1;
if (!memccpy(ep,
firstnonnull(emptytonull(getenv("PATH")),
"/bin:/usr/local/bin:/usr/bin"),
'\0', sizeof(ep))) {
return enomem();
}
pathtok = ep;
while ((path = strsep(&pathtok, IsWindows() ? ";" : ":"))) {
if (strchr(path, '=')) continue;
if ((rc = accesscmd(pathname, path, name, namelen)) != -1) {
break;
}
}
return rc;
}
static char *mkcmdquery(const char *name, size_t namelen,
char scratch[hasatleast PATH_MAX]) {
char *p;
if (namelen + 1 + 1 > PATH_MAX) return NULL;
p = mempcpy(scratch, name, namelen);
*p++ = '=';
*p++ = '\0';
if (IsWindows() || IsXnu()) strntolower(scratch, namelen);
return &scratch[0];
}
/**
* Resolves full pathname of executable.
*
* @return execve()'able path, or NULL w/ errno
* @errno ENOENT, EACCES, ENOMEM
* @see free(), execvpe()
*/
char *commandv(const char *name, char pathbuf[hasatleast PATH_MAX]) {
char *p;
size_t len;
int rc, olderr;
olderr = errno;
if (!(len = strlen(name))) return PROGN(enoent(), NULL);
if (memchr(name, '=', len)) return PROGN(einval(), NULL);
if ((IsWindows() &&
((rc = accesscmd(pathbuf, kNtSystemDirectory, name, len)) != -1 ||
(rc = accesscmd(pathbuf, kNtWindowsDirectory, name, len)) != -1)) ||
(rc = accesscmd(pathbuf, "", name, len)) != -1 ||
(!strpbrk(name, "/\\") &&
(rc = searchcmdpath(pathbuf, name, len)) != -1)) {
errno = olderr;
return pathbuf;
} else {
return NULL;
}
}