Bump version to 1.32.0

[oweals/busybox.git] / procps / watch.c

diff --git a/procps/watch.c b/procps/watch.c
index 76d2a87e96abca9985b7b2ab21c2f4dd0b7894d9..059eb1dda7c664064d1034c78b906fe899608b5d 100644 (file)
--- a/procps/watch.c
+++ b/procps/watch.c
@@ -5,14 +5,39 @@
  * Copyright (C) 2001 by Michael Habermann <mhabermann@gmx.de>
  * Copyrigjt (C) Mar 16, 2003 Manuel Novoa III   (mjn3@codepoet.org)
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
+//config:config WATCH
+//config:      bool "watch (4.4 kb)"
+//config:      default y
+//config:      help
+//config:      watch is used to execute a program periodically, showing
+//config:      output to the screen.
+
+//applet:IF_WATCH(APPLET(watch, BB_DIR_BIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_WATCH) += watch.o
+
+//usage:#define watch_trivial_usage
+//usage:       "[-n SEC] [-t] PROG ARGS"
+//usage:#define watch_full_usage "\n\n"
+//usage:       "Run PROG periodically\n"
+//usage:     "\n       -n SEC  Loop period (default 2)"
+//usage:     "\n       -t      Don't print header"
+//usage:
+//usage:#define watch_example_usage
+//usage:       "$ watch date\n"
+//usage:       "Mon Dec 17 10:31:40 GMT 2000\n"
+//usage:       "Mon Dec 17 10:31:42 GMT 2000\n"
+//usage:       "Mon Dec 17 10:31:44 GMT 2000"
 
 /* BB_AUDIT SUSv3 N/A */
 /* BB_AUDIT GNU defects -- only option -n is supported. */
 
 #include "libbb.h"
 
+#define ESC "\033"
+
 // procps 2.0.18:
 // watch [-d] [-n seconds]
 //   [--differences[=cumulative]] [--interval=seconds] command
@@ -24,58 +49,71 @@
 // (procps 3.x and procps 2.x are forks, not newer/older versions of the same)
 
 int watch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int watch_main(int argc, char **argv)
+int watch_main(int argc UNUSED_PARAM, char **argv)
 {
+       duration_t period;
+       char *period_str = (char*) "2";
        unsigned opt;
-       unsigned period = 2;
-       unsigned cmdlen;
-       char *header = NULL;
+       unsigned 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);
+#if 0 // maybe ENABLE_DESKTOP?
+       // procps3 compat - "echo TEST | watch cat" doesn't show TEST:
+       close(STDIN_FILENO);
+       xopen("/dev/null", O_RDONLY);
+#endif
+
+       // "+": stop at first non-option (procps 3.x only); -n NUM
+       // at least one param
+       opt = getopt32(argv, "^+" "dtn:" "\0" "-1", &period_str);
        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
 
+       period = parse_duration_str(period_str);
+       width = (unsigned)-1; // make sure first time new_width != width
+       header = NULL;
        while (1) {
-               printf("\033[H\033[J");
+               /* home; clear to the end of screen */
+               printf(ESC"[H" ESC"[J");
                if (!(opt & 0x2)) { // no -t
-                       int width, len;
-                       char *thyme;
-                       time_t t;
+                       const unsigned time_len = sizeof("1234-67-90 23:56:89");
+
+                       // STDERR_FILENO is procps3 compat:
+                       // "watch ls 2>/dev/null" does not detect tty size
+                       new_width = get_terminal_width(STDERR_FILENO);
+                       if (new_width != width) {
+                               width = new_width;
+                               free(header);
+                               header = xasprintf("Every"
+                                       " %"IF_FLOAT_DURATION(".1")DURATION_FMT"s:"
+                                       " %-*s",
+                                       period,
+                                       (int)width, cmd
+                               );
+                       }
+                       if (time_len < width) {
+                               strftime_YYYYMMDDHHMMSS(
+                                       header + width - time_len,
+                                       time_len,
+                                       /*time_t*:*/ NULL
+                               );
+                       }
 
-                       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);
-                       time(&t);
-                       thyme = ctime(&t);
-                       len = strlen(thyme);
-                       if (len < width)
-                               strcpy(header + width - len, thyme);
-                       puts(header);
+                       // compat: empty line between header and cmd output
+                       printf("%s\n\n", header);
                }
-               fflush(stdout);
+               fflush_all();
                // TODO: 'real' watch pipes cmd's output to itself
                // and does not allow it to overflow the screen
                // (taking into account linewrap!)
                system(cmd);
-               sleep(period);
+               sleep_for_duration(period);
        }
        return 0; // gcc thinks we can reach this :)
 }