watch: shrink (by walter harms <WHarms AT bfs.de>)

watch_main                                           327     263     -64

1 files changed, 23 insertions, 29 deletions

diff --git a/procps/watch.c b/procps/watch.c
index 76d2a87e9..b4955258e 100644
--- a/procps/watch.c
+++ b/procps/watch.c
@@ -28,46 +28,40 @@ int watch_main(int argc, char **argv)
 {
         unsigned opt;
         unsigned period = 2;
-        unsigned cmdlen;
-        char *header = NULL;
+        int width, new_width;
+        char *header;
         char *cmd;
-        char *tmp;
-        char **p;
 
-        opt_complementary = "-1"; // at least one param please
-        opt = getopt32(argv, "+dtn:", &tmp);
-        //if (opt & 0x1) // -d (ignore)
-        //if (opt & 0x2) // -t
-        if (opt & 0x4) period = xatou(tmp);
+        opt_complementary = "-1:n+"; // at least one param; -n NUM
+        // "+": stop at first non-option (procps 3.x only)
+        opt = getopt32(argv, "+dtn:", &period);
         argv += optind;
 
-        p = argv;
-        cmdlen = 1; // 1 for terminal NUL
-        while (*p)
-                cmdlen += strlen(*p++) + 1;
-        tmp = cmd = xmalloc(cmdlen);
-        while (*argv) {
-                tmp += sprintf(tmp, " %s", *argv);
-                argv++;
-        }
-        cmd++; // skip initial space
+        // watch from both procps 2.x and 3.x does concatenation. Example:
+        // watch ls -l "a /tmp" "2>&1" -- ls won't see "a /tmp" as one param
+        cmd = *argv;
+        while (*++argv)
+                cmd = xasprintf("%s %s", cmd, *argv); // leaks cmd
 
+        width = -1; // make sure first time new_width != width
+        header = NULL;
         while (1) {
                 printf("\033[H\033[J");
                 if (!(opt & 0x2)) { // no -t
-                        int width, len;
-                        char *thyme;
+                        const int time_len = sizeof("1234-67-90 23:56:89");
                         time_t t;
 
-                        get_terminal_width_height(STDIN_FILENO, &width, 0);
-                        header = xrealloc(header, width--);
-                        // '%-*s' pads header with spaces to the full width
-                        snprintf(header, width, "Every %ds: %-*s", period, width, cmd);
+                        get_terminal_width_height(STDIN_FILENO, &new_width, NULL);
+                        if (new_width != width) {
+                                width = new_width;
+                                free(header);
+                                header = xasprintf("Every %us: %-*s", period, width, cmd);
+                        }
                         time(&t);
-                        thyme = ctime(&t);
-                        len = strlen(thyme);
-                        if (len < width)
-                                strcpy(header + width - len, thyme);
+                        if (time_len < width)
+                                strftime(header + width - time_len, time_len,
+                                        "%Y-%m-%d %H:%M:%S", localtime(&t));
+
                         puts(header);
                 }
                 fflush(stdout);