[TUHS] Re: forking, Re: [COFF] Re: On Bloat and the Idea of Small Specialized Tools

On Mon, May 13, 2024 at 11:34:38AM +1000, Dave Horsfall wrote: /* * Copyright 1999-2002,2004-2006,2015-2016 BitMover, Inc * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "system.h" void (*spawn_preHook)(int flags, char *av[]) = 0; #ifndef WIN32 pid_t bk_spawnvp(int flags, char *cmdname, char *av[]) { int fd, status; pid_t pid; char *exec; /* Tell the calling process right away if there is no such program */ unless (exec = which((char*)cmdname)) return (-1); if (spawn_preHook) spawn_preHook(flags, av); if (pid = fork()) { /* parent */ free(exec); if (pid == -1) return (pid); unless (flags & (_P_DETACH|_P_NOWAIT)) { if (waitpid(pid, &status, 0) != pid) status = -1; return (status); } return (pid); } else { /* child */ /* * See win32/uwtlib/wapi_intf.c:spawnvp_ex() * We leave nothing open on a detach, but leave * in/out/err open on a normal fork/exec. */ if (flags & _P_DETACH) { unless (getenv("_NO_SETSID")) setsid(); /* close everything to match winblows */ for (fd = 0; fd < 100; fd++) (close)(fd); } else { /* * Emulate having everything except in/out/err * as being marked as close on exec to match winblows. */ for (fd = 3; fd < 100; fd++) (close)(fd); } execv(exec, av); perror(exec); _exit(19); } } #else /* ======== WIN32 ======== */ pid_t bk_spawnvp(int flags, char *cmdname, char *av[]) { pid_t pid; char *exec; /* Tell the calling process right away if there is no such program */ unless (exec = which((char*)cmdname)) return (-1); if (spawn_preHook) spawn_preHook(flags, av); /* * We use our own version of spawn in uwtlib * because the NT spawn() does not work well with tcl */ pid = _spawnvp_ex(flags, exec, av, 1); free(exec); return (pid); } #endif /* WIN32 */