2 * logsave.c --- A program which saves the output of a program until
5 * Copyright (C) 2003 Theodore Ts'o.
8 * This file may be redistributed under the terms of the GNU Public
13 #define _XOPEN_SOURCE 600 /* for inclusion of sa_handler in Solaris */
20 #include <sys/types.h>
35 static int outfd = -1;
36 static int outbufsize = 0;
37 static void *outbuf = 0;
38 static int verbose = 0;
39 static int do_skip = 0;
40 static int skip_mode = 0;
41 static pid_t child_pid = -1;
43 static void usage(char *progname)
45 printf("Usage: %s [-asv] logfile program\n", progname);
50 #define SEND_CONSOLE 0x02
51 #define SEND_BOTH 0x03
54 * Helper function that does the right thing if write returns a
55 * partial write, or an EGAIN/EINTR error.
57 static int write_all(int fd, const char *buf, size_t count)
63 ret = write(fd, buf, count);
65 if ((errno == EAGAIN) || (errno == EINTR))
76 static void send_output(const char *buffer, int c, int flag)
85 if (flag & SEND_CONSOLE) {
90 for (d=0; d < cnt; d++) {
92 (cp[d] == '\001' || cp[d] == '\002')) {
104 if (!(flag & SEND_LOG))
107 write_all(outfd, buffer, c);
109 n = realloc(outbuf, outbufsize + c);
112 memcpy(((char *)outbuf)+outbufsize, buffer, c);
118 static int do_read(int fd)
121 char buffer[4096], *cp, *sep;
123 c = read(fd, buffer, sizeof(buffer)-1);
127 send_output(buffer, c, SEND_CONSOLE);
132 cp = strchr(cp, '\002');
139 sep = strchr(cp, '\001');
142 send_output(cp, 0, SEND_LOG);
150 send_output(buffer, c, SEND_BOTH);
154 static void signal_term(int sig)
157 kill(child_pid, sig);
160 static int run_program(char **argv)
175 memset(&sa, 0, sizeof(struct sigaction));
176 sa.sa_handler = signal_term;
177 sigaction(SIGINT, &sa, 0);
178 sigaction(SIGTERM, &sa, 0);
180 sa.sa_flags = SA_RESTART;
190 dup2(fds[1],1); /* fds[1] replaces stdout */
191 dup2(fds[1],2); /* fds[1] replaces stderr */
192 close(fds[0]); /* don't need this here */
195 execvp(argv[0], argv);
202 while (!(waitpid(pid, &status, WNOHANG ))) {
209 if ( WIFEXITED(status) ) {
210 rc = WEXITSTATUS(status);
212 send_output(argv[0], 0, SEND_BOTH);
213 sprintf(buffer, " exited with status code %d\n", rc);
214 send_output(buffer, 0, SEND_BOTH);
217 if (WIFSIGNALED(status)) {
218 send_output(argv[0], 0, SEND_BOTH);
219 sprintf(buffer, "died with signal %d\n",
221 send_output(buffer, 0, SEND_BOTH);
229 static int copy_from_stdin(void)
236 ((c < 0) && ((errno == EAGAIN) || (errno == EINTR)))) {
252 int main(int argc, char **argv)
256 int openflags = O_CREAT|O_WRONLY|O_TRUNC;
257 int send_flag = SEND_LOG;
261 while ((c = getopt(argc, argv, "+asv")) != EOF) {
264 openflags &= ~O_TRUNC;
265 openflags |= O_APPEND;
272 send_flag |= SEND_CONSOLE;
276 if (optind == argc || optind+1 == argc)
278 outfn = argv[optind];
283 outfd = open(outfn, openflags, 0644);
284 do_stdin = !strcmp(argv[0], "-");
286 send_output("Log of ", 0, send_flag);
288 send_output("stdin", 0, send_flag);
290 for (cpp = argv; *cpp; cpp++) {
291 send_output(*cpp, 0, send_flag);
292 send_output(" ", 0, send_flag);
295 send_output("\n", 0, send_flag);
297 send_output(ctime(&t), 0, send_flag);
298 send_output("\n", 0, send_flag);
301 rc = copy_from_stdin();
303 rc = run_program(argv);
305 send_output("\n", 0, send_flag);
307 send_output(ctime(&t), 0, send_flag);
308 send_output("----------------\n", 0, send_flag);
318 printf("Backgrounding to save %s later\n",
322 setsid(); /* To avoid getting killed by init */
324 outfd = open(outfn, openflags, 0644);
327 write_all(outfd, outbuf, outbufsize);