Correctly pass along SIGINT to child processes.

[bup.git] / main.py

diff --git a/main.py b/main.py
index 36f65443d2aa67f5012562321b541f74e6568e82..50eb24454154b216287563e1ad5c773d27bb24b9 100755 (executable)
--- a/main.py
+++ b/main.py
@@ -1,5 +1,5 @@
 #!/usr/bin/env python
-import sys, os, subprocess
+import sys, os, subprocess, signal
 
 argv = sys.argv
 exe = argv[0]
@@ -10,23 +10,67 @@ libpath = os.path.join(exepath, 'lib')
 cmdpath = os.path.join(exepath, 'cmd')
 sys.path[:0] = [libpath]
 os.environ['PYTHONPATH'] = libpath + ':' + os.environ.get('PYTHONPATH', '')
+os.environ['BUP_MAIN_EXE'] = os.path.abspath(exe)
 
 from bup.helpers import *
 
+
+def columnate(l, prefix):
+    l = l[:]
+    clen = max(len(s) for s in l)
+    ncols = (78 - len(prefix)) / (clen + 2)
+    if ncols <= 1:
+        ncols = 1
+        clen = 0
+    cols = []
+    while len(l) % ncols:
+        l.append('')
+    rows = len(l)/ncols
+    for s in range(0, len(l), rows):
+        cols.append(l[s:s+rows])
+    for row in zip(*cols):
+        print prefix + ''.join(('%-*s' % (clen+2, s)) for s in row)
+
+
 def usage():
-    log('Usage: bup <subcmd> <options...>\n\n')
-    log('Available subcommands:\n')
+    log('Usage: bup <command> <options...>\n\n')
+    common = dict(
+        ftp = 'Browse backup sets using an ftp-like client',
+        fsck = 'Check backup sets for damage and add redundancy information',
+        fuse = 'Mount your backup sets as a filesystem',
+        help = 'Print detailed help for the given command',
+        index = 'Create or display the index of files to back up',
+        join = 'Retrieve a file backed up using "bup split"',
+        ls = 'Browse the files in your backup sets',
+        midx = 'Index objects to speed up future backups',
+        save = 'Save files into a backup set (note: run "bup index" first)',
+        split = 'Split a single file into its own backup set',
+    )
+
+    log('Common commands:\n')
+    for cmd,synopsis in sorted(common.items()):
+        print '    %-10s %s' % (cmd, synopsis)
+    log('\n')
+    
+    log('Other available commands:\n')
+    cmds = []
     for c in sorted(os.listdir(cmdpath) + os.listdir(exepath)):
         if c.startswith('bup-') and c.find('.') < 0:
-            log('\t%s\n' % c[4:])
+            cname = c[4:]
+            if cname not in common:
+                cmds.append(c[4:])
+    columnate(cmds, '    ')
+    log('\n')
+    
+    log("See 'bup help <command>' for more information on " +
+        "a specific command.\n")
     sys.exit(99)
 
+
 if len(argv) < 2 or not argv[1] or argv[1][0] == '-':
     usage()
 
 subcmd = argv[1]
-if subcmd == 'help':
-    usage()
 
 def subpath(s):
     sp = os.path.join(exepath, 'bup-%s' % s)
@@ -40,28 +84,43 @@ if not os.path.exists(subpath(subcmd)):
 
 
 already_fixed = atoi(os.environ.get('BUP_FORCE_TTY'))
-if subcmd in ['ftp']:
+if subcmd in ['ftp', 'help']:
     already_fixed = True
 fix_stdout = not already_fixed and os.isatty(1)
 fix_stderr = not already_fixed and os.isatty(2)
 
 def force_tty():
     if fix_stdout or fix_stderr:
-        os.environ['BUP_FORCE_TTY'] = '1'
+        amt = (fix_stdout and 1 or 0) + (fix_stderr and 2 or 0)
+        os.environ['BUP_FORCE_TTY'] = str(amt)
+    os.setsid()  # make sure ctrl-c is sent just to us, not to child too
 
 if fix_stdout or fix_stderr:
     realf = fix_stderr and 2 or 1
     n = subprocess.Popen([subpath('newliner')],
                          stdin=subprocess.PIPE, stdout=os.dup(realf),
                          close_fds=True, preexec_fn=force_tty)
-    outf = fix_stdout and n.stdin.fileno() or 1
-    errf = fix_stderr and n.stdin.fileno() or 2
+    outf = fix_stdout and n.stdin.fileno() or None
+    errf = fix_stderr and n.stdin.fileno() or None
 else:
     n = None
-    outf = 1
-    errf = 2
+    outf = None
+    errf = None
+
+
+class SigException(Exception):
+    def __init__(self, signum):
+        self.signum = signum
+        Exception.__init__(self, 'signal %d received' % signum)
+def handler(signum, frame):
+    raise SigException(signum)
+
+signal.signal(signal.SIGTERM, handler)
+signal.signal(signal.SIGINT, handler)
 
 ret = 95
+p = None
+killsig = signal.SIGTERM
 try:
     try:
         p = subprocess.Popen([subpath(subcmd)] + argv[2:],
@@ -70,9 +129,14 @@ try:
     except OSError, e:
         log('%s: %s\n' % (subpath(subcmd), e))
         ret = 98
-    except KeyboardInterrupt, e:
+    except SigException, e:
+        log('\nbup: %s\n' % e)
+        killsig = e.signum
         ret = 94
 finally:
+    if p and p.poll() == None:
+        os.kill(p.pid, killsig)
+        p.wait()
     if n:
         n.stdin.close()
         try: