kill: use control structure to pass user input to functions

This should make it easier to understand how the program works.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/misc-utils/kill.c b/misc-utils/kill.c
index c9c1bda1a2e3545815daf2c4bc73de7efe4918aa..70ca7584e051e5397feacc36cb3b334496a5c0c7 100644 (file)
--- a/misc-utils/kill.c
+++ b/misc-utils/kill.c
@@ -62,6 +62,16 @@ enum {
        KILL_OUTPUT_WIDTH = 72
 };
 
+struct kill_control {
+       char *arg;
+       pid_t pid;
+       int numsig;
+       unsigned int
+               check_all:1,
+               do_kill:1,
+               do_pid:1;
+};
+
 struct signv {
        const char *name;
        int val;
@@ -147,10 +157,10 @@ struct signv {
 
 static int arg_to_signum(char *arg, int mask);
 static void nosig(char *name);
-static void printsig(int sig);
+static void printsig(const struct kill_control *ctl);
 static void printsignals(FILE *fp, int pretty);
 static void __attribute__((__noreturn__)) usage(FILE *out);
-static int kill_verbose(char *procname, int pid, int sig);
+static int kill_verbose(const struct kill_control *ctl);
 
 #ifdef HAVE_SIGQUEUE
 static int use_sigval;
@@ -159,21 +169,20 @@ static union sigval sigdata;
 
 int main(int argc, char **argv)
 {
-       int errors, numsig, pid;
-       char *ep, *arg;
-       int do_pid, do_kill, check_all;
+       struct kill_control ctl;
+       char *arg;
+       int errors = EXIT_SUCCESS;
 
        setlocale(LC_ALL, "");
        bindtextdomain(PACKAGE, LOCALEDIR);
        textdomain(PACKAGE);
        atexit(close_stdout);
+       memset(&ctl, 0, sizeof(ctl));
 
-       numsig = SIGTERM;
-       do_pid = (!strcmp(program_invocation_short_name, "pid"));       /* Yecch */
-       if (do_pid)     /* FIXME: remove in March 2016.  */
+       ctl.numsig = SIGTERM;
+       ctl.do_pid = (!strcmp(program_invocation_short_name, "pid"));   /* Yecch */
+       if (ctl.do_pid) /* FIXME: remove in March 2016.  */
                warnx(_("use of 'kill --pid' option as command name is deprecated"));
-       do_kill = 0;
-       check_all = 0;
        /* Loop through the arguments.  Actually, -a is the only option
         * can be used with other options.  The 'kill' is basically a
         * one-option-at-most program. */
@@ -194,7 +203,7 @@ int main(int argc, char **argv)
                        usage(stdout);
 
                if (!strcmp(arg, "-a") || !strcmp(arg, "--all")) {
-                       check_all++;
+                       ctl.check_all = 1;
                        continue;
                }
                if (!strcmp(arg, "-l") || !strcmp(arg, "--list")) {
@@ -206,18 +215,18 @@ int main(int argc, char **argv)
                                usage(stderr);
                        /* argc == 2, accept "kill -l $?" */
                        arg = argv[1];
-                       if ((numsig = arg_to_signum(arg, 1)) < 0)
+                       if ((ctl.numsig = arg_to_signum(arg, 1)) < 0)
                                errx(EXIT_FAILURE, _("unknown signal: %s"),
                                     arg);
-                       printsig(numsig);
+                       printsig(&ctl);
                        return EXIT_SUCCESS;
                }
                /* for compatibility with procps kill(1) */
                if (!strncmp(arg, "--list=", 7) || !strncmp(arg, "-l=", 3)) {
                        char *p = strchr(arg, '=') + 1;
-                       if ((numsig = arg_to_signum(p, 1)) < 0)
+                       if ((ctl.numsig = arg_to_signum(p, 1)) < 0)
                                errx(EXIT_FAILURE, _("unknown signal: %s"), p);
-                       printsig(numsig);
+                       printsig(&ctl);
                        return EXIT_SUCCESS;
                }
                if (!strcmp(arg, "-L") || !strcmp(arg, "--table")) {
@@ -225,20 +234,20 @@ int main(int argc, char **argv)
                        return EXIT_SUCCESS;
                }
                if (!strcmp(arg, "-p") || !strcmp(arg, "--pid")) {
-                       do_pid++;
-                       if (do_kill)
+                       ctl.do_pid = 1;
+                       if (ctl.do_kill)
                                usage(stderr);
                        continue;
                }
                if (!strcmp(arg, "-s") || !strcmp(arg, "--signal")) {
                        if (argc < 2)
                                usage(stderr);
-                       do_kill++;
-                       if (do_pid)
+                       ctl.do_kill = 1;
+                       if (ctl.do_pid)
                                usage(stderr);
                        argc--, argv++;
                        arg = *argv;
-                       if ((numsig = arg_to_signum(arg, 0)) < 0) {
+                       if ((ctl.numsig = arg_to_signum(arg, 0)) < 0) {
                                nosig(arg);
                                return EXIT_FAILURE;
                        }
@@ -264,49 +273,49 @@ int main(int argc, char **argv)
                 * number).  In case of doubt POSIX tells us to assume a
                 * signal.  If a signal has been parsed, assume it is a
                 * pid, break.  */
-               if (do_kill)
+               if (ctl.do_kill)
                        break;
                arg++;
-               if ((numsig = arg_to_signum(arg, 0)) < 0)
+               if ((ctl.numsig = arg_to_signum(arg, 0)) < 0)
                        usage(stderr);
-               do_kill++;
-               if (do_pid)
+               ctl.do_kill = 1;
+               if (ctl.do_pid)
                        usage(stderr);
                continue;
        }
        if (!*argv)
                usage(stderr);
-       if (do_pid)
-               numsig = -1;
+       if (ctl.do_pid)
+               ctl.numsig = -1;
 
        /* We are done with the options.  The rest of the arguments
         * should be process ids and names, kill them.  */
-       for (errors = 0; (arg = *argv) != NULL; argv++) {
-               pid = strtol(arg, &ep, 10);
+       for (/* nothing */; (ctl.arg = *argv) != NULL; argv++) {
+               char *ep;
+
+               ctl.pid = strtol(ctl.arg, &ep, 10);
                if (!*ep)
-                       errors += kill_verbose(arg, pid, numsig);
+                       errors |= kill_verbose(&ctl);
                else {
                        struct proc_processes *ps = proc_open_processes();
                        int ct = 0;
 
                        if (!ps)
                                continue;
-                       if (!check_all)
+                       if (ctl.check_all)
                                proc_processes_filter_by_uid(ps, getuid());
-                       proc_processes_filter_by_name(ps, arg);
-                       while (proc_next_pid(ps, &pid) == 0) {
-                               errors += kill_verbose(arg, pid, numsig);
+                       proc_processes_filter_by_name(ps, ctl.arg);
+                       while (proc_next_pid(ps, &(ctl.pid)) == 0) {
+                               errors |= kill_verbose(&ctl);
                                ct++;
                        }
                        if (!ct) {
-                               errors++;
-                               warnx(_("cannot find process \"%s\""), arg);
+                               errors = EXIT_FAILURE;
+                               warnx(_("cannot find process \"%s\""), ctl.arg);
                        }
                        proc_close_processes(ps);
                }
        }
-       if (errors != 0)
-               errors = EXIT_FAILURE;
        return errors;
 }
 
@@ -376,23 +385,23 @@ static void nosig(char *name)
        printsignals(stderr, 1);
 }
 
-static void printsig(int sig)
+static void printsig(const struct kill_control *ctl)
 {
        size_t n;
 
        for (n = 0; n < ARRAY_SIZE(sys_signame); n++) {
-               if (sys_signame[n].val == sig) {
+               if (sys_signame[n].val == ctl->numsig) {
                        printf("%s\n", sys_signame[n].name);
                        return;
                }
        }
 #ifdef SIGRTMIN
-       if (SIGRTMIN <= sig && sig <= SIGRTMAX) {
-               printf("RT%d\n", sig - SIGRTMIN);
+       if (SIGRTMIN <= ctl->numsig && ctl->numsig <= SIGRTMAX) {
+               printf("RT%d\n", ctl->numsig - SIGRTMIN);
                return;
        }
 #endif
-       printf("%d\n", sig);
+       printf("%d\n", ctl->numsig);
 }
 
 static void pretty_print_signal(FILE *fp, size_t term_width, size_t *lpos,
@@ -462,23 +471,23 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
        exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
 }
 
-static int kill_verbose(char *procname, pid_t pid, int sig)
+static int kill_verbose(const struct kill_control *ctl)
 {
        int rc = 0;
 
-       if (sig < 0) {
-               printf("%ld\n", (long)pid);
+       if (ctl->numsig < 0) {
+               printf("%ld\n", (long) ctl->pid);
                return 0;
        }
 #ifdef HAVE_SIGQUEUE
        if (use_sigval)
-               rc = sigqueue(pid, sig, sigdata);
+               rc = sigqueue(ctl->pid, ctl->numsig, sigdata);
        else
 #endif
-               rc = kill(pid, sig);
+               rc = kill(ctl->pid, ctl->numsig);
        if (rc < 0) {
-               warn(_("sending signal to %s failed"), procname);
-               return 1;
+               warn(_("sending signal to %s failed"), ctl->arg);
+               return EXIT_FAILURE;
        }
-       return 0;
+       return EXIT_SUCCESS;
 }