74 lines
1.5 KiB
Python
74 lines
1.5 KiB
Python
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# Module 'commands'
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#
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# Various tools for executing commands and looking at their output and status.
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import rand
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import posix
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import path
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# Get 'ls -l' status for an object into a string
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#
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def getstatus(file):
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return getoutput('ls -ld' + mkarg(file))
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# Get the output from a shell command into a string.
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# The exit status is ignored; a trailing newline is stripped.
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# Assume the command will work with ' >tempfile 2>&1' appended.
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# XXX This should use posix.popen() instead, should it exist.
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#
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def getoutput(cmd):
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return getstatusoutput(cmd)[1]
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# Ditto but preserving the exit status.
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# Returns a pair (sts, output)
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#
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def getstatusoutput(cmd):
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tmp = '/usr/tmp/wdiff' + `rand.rand()`
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sts = -1
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try:
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sts = posix.system(cmd + ' >' + tmp + ' 2>&1')
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text = readfile(tmp)
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finally:
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altsts = posix.system('rm -f ' + tmp)
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if text[-1:] = '\n': text = text[:-1]
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return sts, text
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# Return a string containing a file's contents.
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#
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def readfile(fn):
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fp = open(fn, 'r')
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a = ''
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n = 8096
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while 1:
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b = fp.read(n)
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if not b: break
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a = a + b
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return a
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# Make command argument from directory and pathname (prefix space, add quotes).
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#
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def mk2arg(head, x):
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return mkarg(path.cat(head, x))
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# Make a shell command argument from a string.
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# Two strategies: enclose in single quotes if it contains none;
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# otherwis, enclose in double quotes and prefix quotable characters
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# with backslash.
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#
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def mkarg(x):
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if '\'' not in x:
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return ' \'' + x + '\''
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s = ' "'
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for c in x:
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if c in '\\$"':
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s = s + '\\'
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s = s + c
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s = s + '"'
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return s
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