Added some options to do-until.

2 files changed, 95 insertions, 12 deletions

diff --git a/do-until b/do-until
index d9dc863..be6efee 100755
--- a/do-until
+++ b/do-until
@@ -1,12 +1,66 @@
-#!/bin/sh
-#
-# do-until - run a command until it succeeds
-#
-# Lars Wirzenius <liw@liw.fi>
-
-cmdline="$@"
-while ! $cmdline
-do
-    echo "Command failed, trying again in 1 second"
-    sleep 1
-done
+#!/usr/bin/python
+
+
+"""Run a command until it succeeds.
+
+Lars Wirzenius <liw@liw.fi>
+"""
+
+
+import optparse
+import subprocess
+import sys
+import time
+
+
+def do_until(options, argv):
+    tries = 0
+    while options.max_tries == 0 or tries < options.max_tries:
+        tries += 1
+        if options.verbose:
+            sys.stderr.write("do-until: attempt #%d: %s\n" % 
+                             (tries, " ".join(argv)))
+        if options.no_act:
+            sys.stderr.write("do-until: not running command, pretending it "
+                             "works anyway\n")
+            break
+        else:
+            p = subprocess.Popen(argv)
+            p.communicate()
+            if p.returncode == 0:
+                break
+        sys.stderr.write("do-until: command failed, "
+                         "trying again in %d second(s)\n" % options.sleep)
+        time.sleep(options.sleep)
+
+
+def parse_args(args):
+    parser = optparse.OptionParser()
+    parser.add_option("-n", "--no-act", action="store_true",
+                      help="Do not run command, just pretend to do it, and "
+                           "pretend that it succeeds.")
+    parser.add_option("-v", "--verbose", action="store_true",
+                      help="Print command before executing it.")
+    parser.add_option("--sleep", type="int", default=1, metavar="SECS",
+                      help="Wait SECS seconds before re-trying a command. "
+                           "(Default is %default.)")
+    parser.add_option("--max-tries", type="int", default=0, metavar="COUNT",
+                      help="Try at most COUNT times, with 0 meaning forever. "
+                           "(Default is %default.)")
+    
+    options, argv = parser.parse_args(args)
+
+    return options, argv
+
+
+def main():
+    try:
+        options, argv = parse_args(sys.argv[1:])
+        if argv:
+            do_until(options, argv)
+    except KeyboardInterrupt:
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/do-until.1 b/do-until.1
index 16775e7..aa43aec 100644
--- a/do-until.1
+++ b/do-until.1
@@ -3,6 +3,12 @@
 do-until \- repeat a command until it succeeds
 .SH SYNOPSIS
 .B do-until 
+.RB [ -nv ]
+.RB [ --no-act ]
+.RB [ --verbose ]
+.RB [ --max-tries = \fICOUNT ]
+.RB [ --sleep = \fISECS ]
+.RB [ -- ]
 .I command
 .IR arg ...
 .SH DESCRIPTION
@@ -30,3 +36,26 @@ If this matters, you may need to invoke the command you need via
 "sh -c 'foo > bar'" 
 or some similar incantation.
 See your shell manual for details.
+.SH OPTIONS
+.TP
+.BR -h ", " --help
+Write out a short usage summary.
+.TP
+.BR -n ", " --no-act
+Do not run the command, just pretend to run it.
+Also pretend it always succeeds.
+.TP
+.BR -v ", " --verbose
+Write the command out before executing it.
+.TP
+.BR --sleep =\fISECS
+Wait 
+.I SECS 
+seconds before re-trying a command. 
+(Default is 1.)
+.TP
+.BR --max-tries =\fICOUNT
+Try at most 
+COUNT 
+times, with 0 meaning forever. 
+(Default is 0.)