/* Emulate waitpid on systems that just have wait. Copyright (C) 1994 Free Software Foundation, Inc. This file is part of GNU DIFF. GNU DIFF 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; either version 2, or (at your option) any later version. GNU DIFF 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. */ #include "vms.h" #define WAITPID_CHILDREN 8 static pid_t waited_pid[WAITPID_CHILDREN]; static int waited_status[WAITPID_CHILDREN]; pid_t waitpid (pid, stat_loc, options) pid_t pid; int *stat_loc; int options; { int i; pid_t p; if (!options && (0 < pid || pid == -1)) { /* If we have already waited for this child, return it immediately. */ for (i = 0; i < WAITPID_CHILDREN; i++) { p = waited_pid[i]; if (p && (p == pid || pid == -1)) { waited_pid[i] = 0; goto success; } } /* The child has not returned yet; wait for it, accumulating status. */ for (i = 0; i < WAITPID_CHILDREN; i++) if (! waited_pid[i]) { p = wait (&waited_status[i]); if (p < 0) return p; if (p == pid || pid == -1) goto success; waited_pid[i] = p; } } /* We cannot emulate this wait call, e.g. because of too many children. */ abort (); success: if (stat_loc) *stat_loc = waited_status[i]; return p; }