Mercurial > hg
view contrib/chg/util.c @ 28084:3fc45956c978
chg: initialize sigaction fields more reliably
It seems calling memset() and sigemptyset() is common pattern to initialize
sigaction. And strictly speaking, sigset_t must be initialized by sigemptyset()
or sigfillset(). I saw git and uwsgi do that way, so let's follow them.
author | Yuya Nishihara <yuya@tcha.org> |
---|---|
date | Fri, 29 Jan 2016 22:42:22 +0900 |
parents | 726f8d6cc324 |
children | c6705c6303dd |
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/* * Utility functions * * Copyright (c) 2011 Yuya Nishihara <yuya@tcha.org> * * This software may be used and distributed according to the terms of the * GNU General Public License version 2 or any later version. */ #include <signal.h> #include <stdarg.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/types.h> #include <sys/wait.h> #include <unistd.h> #include "util.h" void abortmsg(const char *fmt, ...) { va_list args; va_start(args, fmt); fputs("\033[1;31mchg: abort: ", stderr); vfprintf(stderr, fmt, args); fputs("\033[m\n", stderr); va_end(args); exit(255); } static int debugmsgenabled = 0; void enabledebugmsg(void) { debugmsgenabled = 1; } void debugmsg(const char *fmt, ...) { if (!debugmsgenabled) return; va_list args; va_start(args, fmt); fputs("\033[1;30mchg: debug: ", stderr); vfprintf(stderr, fmt, args); fputs("\033[m\n", stderr); va_end(args); } /* * Execute a shell command in mostly the same manner as system(), with the * give environment variables, after chdir to the given cwd. Returns a status * code compatible with the Python subprocess module. */ int runshellcmd(const char *cmd, const char *envp[], const char *cwd) { enum { F_SIGINT = 1, F_SIGQUIT = 2, F_SIGMASK = 4, F_WAITPID = 8 }; unsigned int doneflags = 0; int status = 0; struct sigaction newsa, oldsaint, oldsaquit; sigset_t oldmask; /* block or mask signals just as system() does */ memset(&newsa, 0, sizeof(newsa)); newsa.sa_handler = SIG_IGN; newsa.sa_flags = 0; if (sigemptyset(&newsa.sa_mask) < 0) goto done; if (sigaction(SIGINT, &newsa, &oldsaint) < 0) goto done; doneflags |= F_SIGINT; if (sigaction(SIGQUIT, &newsa, &oldsaquit) < 0) goto done; doneflags |= F_SIGQUIT; if (sigaddset(&newsa.sa_mask, SIGCHLD) < 0) goto done; if (sigprocmask(SIG_BLOCK, &newsa.sa_mask, &oldmask) < 0) goto done; doneflags |= F_SIGMASK; pid_t pid = fork(); if (pid < 0) goto done; if (pid == 0) { sigaction(SIGINT, &oldsaint, NULL); sigaction(SIGQUIT, &oldsaquit, NULL); sigprocmask(SIG_SETMASK, &oldmask, NULL); if (cwd && chdir(cwd) < 0) _exit(127); const char *argv[] = {"sh", "-c", cmd, NULL}; if (envp) { execve("/bin/sh", (char **)argv, (char **)envp); } else { execv("/bin/sh", (char **)argv); } _exit(127); } else { if (waitpid(pid, &status, 0) < 0) goto done; doneflags |= F_WAITPID; } done: if (doneflags & F_SIGINT) sigaction(SIGINT, &oldsaint, NULL); if (doneflags & F_SIGQUIT) sigaction(SIGQUIT, &oldsaquit, NULL); if (doneflags & F_SIGMASK) sigprocmask(SIG_SETMASK, &oldmask, NULL); /* no way to report other errors, use 127 (= shell termination) */ if (!(doneflags & F_WAITPID)) return 127; if (WIFEXITED(status)) return WEXITSTATUS(status); if (WIFSIGNALED(status)) return -WTERMSIG(status); return 127; }