kill grep on error; small cleanups

diff --git a/fag.c b/fag.c
index 64799789fd8fc412f2b7d541288d5f8cc8069fea..0d7e6d9e1b4e2d608d7df9eadc4ff5ed30a3ad86 100644 (file)
--- a/fag.c
+++ b/fag.c
@@ -1,5 +1,4 @@
 /* forkaftergrep (C) 2017 Tobias Girstmair, GPLv3 */
-//TODO: if grep exits with an error, fag thinks a match was found
 
 #define _XOPEN_SOURCE 500
 #define _DEFAULT_SOURCE
@@ -17,13 +16,15 @@
 
 int main (int argc, char** argv) {
        struct opt opts = {0, 0, 0, NULL, NULL, STDOUT_FILENO, "-q"};
+       /* `-q': don't print anything; exit with 0 on match; with 1 on error. used to interface with `grep' */
        int opt;
        opterr = 0;
 
        /* generate grep options string */
-       /* `-q': don't print anything; exit with 0 on match; with 1 on error */
        char* p = opts.grepopt+2; /* move cursor behind `q' */
 
+       signal (SIGPIPE, SIG_IGN); /* ignore broken pipe between fag and grep */
+
 
        /* the `+' forces getopt to stop at the first non-option */
        while ((opt = getopt (argc, argv, "+t:k::eVhvEFGPiwxyU")) != -1) {
@@ -44,10 +45,11 @@ int main (int argc, char** argv) {
                        fprintf (stderr, VERTEXT USAGE
                                "Options:\n"
                                "\t-t N\ttimeout after N seconds\n"
-                               "\t-k [M]\tsend signal M to child after timeout (default: 15/SIGTERM)\n"
+                               "\t-k[M]\tsend signal M to child after timeout (default: 15/SIGTERM)\n"
                                "\t-e\tgrep on stderr instead of stdout\n"
                                "\t-V\tbe verbose; print PROGRAM's stdout/stderr to stderr\n"
-                               "\t-[EFGPiwxyU]\t grep options\n", argv[0]);
+                               "\t-[EFP]\tgrep: matcher selection\n"
+                               "\t-[iwxU]\tgrep: matching control\n", argv[0]);
                        return EX_OK;
                case 'v':
                        fprintf (stderr, VERTEXT);
@@ -62,7 +64,7 @@ int main (int argc, char** argv) {
                        return EX_USAGE;
                }
        }
-       *p = '\0'; /* finish grep_options string */
+       *p = '\0'; /* terminate grep_options string */
 
        /* the first non-option argument is the search string */
        if (optind < argc) {
@@ -80,8 +82,6 @@ int main (int argc, char** argv) {
                return EX_USAGE;
        }
 
-       signal (SIGPIPE, SIG_IGN); /* ignore broken pipe between fag and grep */
-
        int retval = fork_after_grep (opts);
 
        return retval;
@@ -171,14 +171,14 @@ int fork_after_grep (struct opt opts) {
                                                fprintf (stderr, "read error (userprog): %s", strerror (errno));
                                                close (pipefd[0]);
                                                close (grep_pipefd[1]);
-                                               //TODO: kill grep?
+                                               kill (grep_cpid, SIGTERM);
                                                return EX_IOERR;
                                        }
                                } else if (nbytes == 0) {
                                        fprintf (stderr, "Child program exited prematurely (userprog).\n");
                                        close (pipefd[0]);
                                        close (grep_pipefd[1]);
-                                       //TODO: kill grep?
+                                       kill (grep_cpid, SIGTERM);
                                        if (waitpid (cpid, &status, WNOHANG) > 0 && WIFEXITED (status)) {
                                                return WEXITSTATUS (status);
                                        }
@@ -192,7 +192,6 @@ int fork_after_grep (struct opt opts) {
                                        write(grep_pipefd[1], buf, nbytes); /* can cause SIGPIPE if grep exited, therefore signal will be ignored */
                                }
 
-                               // TODO: exits with `0' even if `grep' exits with code > 0 !
                                if (waitpid (grep_cpid, &grep_status, WNOHANG) > 0 && WIFEXITED (grep_status)) {
                                        close (grep_pipefd[1]);
 
@@ -225,7 +224,7 @@ int fork_after_grep (struct opt opts) {
                                                if (opts.kill_sig > 0) kill (cpid, opts.kill_sig);
                                                close (pipefd[0]);
                                                close (grep_pipefd[1]);
-                                               //TODO: kill grep?
+                                               kill (grep_cpid, SIGTERM);
                                                return EX_UNAVAILABLE;
                                        }
                                }