From a19a216bc60160c162e616145ef091dd18ce4e61 Mon Sep 17 00:00:00 2001 From: Skip Montanaro Date: Tue, 16 Feb 2021 14:40:46 -0600 Subject: Python 0.9.1 as posted in alt.sources --- lib/commands.py | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 lib/commands.py (limited to 'lib/commands.py') diff --git a/lib/commands.py b/lib/commands.py new file mode 100644 index 0000000..3cb6e69 --- /dev/null +++ b/lib/commands.py @@ -0,0 +1,77 @@ +# Module 'commands' +# +# Various tools for executing commands and looking at their output and status. + +import rand +import posix +import stat +import path + + +# Get 'ls -l' status for an object into a string +# +def getstatus(file): + return getoutput('ls -ld' + mkarg(file)) + + +# Get the output from a shell command into a string. +# The exit status is ignored; a trailing newline is stripped. +# Assume the command will work with ' >tempfile 2>&1' appended. +# XXX This should use posix.popen() instead, should it exist. +# +def getoutput(cmd): + return getstatusoutput(cmd)[1] + + +# Ditto but preserving the exit status. +# Returns a pair (sts, output) +# +def getstatusoutput(cmd): + tmp = '/usr/tmp/wdiff' + `rand.rand()` + sts = -1 + try: + sts = posix.system(cmd + ' >' + tmp + ' 2>&1') + text = readfile(tmp) + finally: + altsts = posix.system('rm -f ' + tmp) + if text[-1:] = '\n': text = text[:-1] + return sts, text + + +# Return a string containing a file's contents. +# +def readfile(fn): + st = posix.stat(fn) + size = st[stat.ST_SIZE] + if not size: return '' + try: + fp = open(fn, 'r') + except: + raise posix.error, 'readfile(' + fn + '): open failed' + try: + return fp.read(size) + except: + raise posix.error, 'readfile(' + fn + '): read failed' + + +# Make command argument from directory and pathname (prefix space, add quotes). +# +def mk2arg(head, x): + return mkarg(path.cat(head, x)) + + +# Make a shell command argument from a string. +# Two strategies: enclose in single quotes if it contains none; +# otherwis, enclose in double quotes and prefix quotable characters +# with backslash. +# +def mkarg(x): + if '\'' not in x: + return ' \'' + x + '\'' + s = ' "' + for c in x: + if c in '\\$"': + s = s + '\\' + s = s + c + s = s + '"' + return s -- cgit v1.2.3