1 """Execute shell commands via os.popen() and return status, output. 2 3 Interface summary: 4 5 import commands 6 7 outtext = commands.getoutput(cmd) 8 (exitstatus, outtext) = commands.getstatusoutput(cmd) 9 outtext = commands.getstatus(file) # returns output of "ls -ld file" 10 11 A trailing newline is removed from the output string. 12 13 Encapsulates the basic operation: 14 15 pipe = os.popen('{ ' + cmd + '; } 2>&1', 'r') 16 text = pipe.read() 17 sts = pipe.close() 18 19 [Note: it would be nice to add functions to interpret the exit status.] 20 """ 21 from warnings import warnpy3k 22 warnpy3k("the commands module has been removed in Python 3.0; " 23 "use the subprocess module instead", stacklevel=2) 24 del warnpy3k 25 26 __all__ = ["getstatusoutput","getoutput","getstatus"] 27 28 # Module 'commands' 29 # 30 # Various tools for executing commands and looking at their output and status. 31 # 32 # NB This only works (and is only relevant) for UNIX. 33 34 35 # Get 'ls -l' status for an object into a string 36 # 37 def getstatus(file): 38 """Return output of "ls -ld <file>" in a string.""" 39 import warnings 40 warnings.warn("commands.getstatus() is deprecated", DeprecationWarning, 2) 41 return getoutput('ls -ld' + mkarg(file)) 42 43 44 # Get the output from a shell command into a string. 45 # The exit status is ignored; a trailing newline is stripped. 46 # Assume the command will work with '{ ... ; } 2>&1' around it.. 47 # 48 def getoutput(cmd): 49 """Return output (stdout or stderr) of executing cmd in a shell.""" 50 return getstatusoutput(cmd)[1] 51 52 53 # Ditto but preserving the exit status. 54 # Returns a pair (sts, output) 55 # 56 def getstatusoutput(cmd): 57 """Return (status, output) of executing cmd in a shell.""" 58 import os 59 pipe = os.popen('{ ' + cmd + '; } 2>&1', 'r') 60 text = pipe.read() 61 sts = pipe.close() 62 if sts is None: sts = 0 63 if text[-1:] == '\n': text = text[:-1] 64 return sts, text 65 66 67 # Make command argument from directory and pathname (prefix space, add quotes). 68 # 69 def mk2arg(head, x): 70 import os 71 return mkarg(os.path.join(head, x)) 72 73 74 # Make a shell command argument from a string. 75 # Return a string beginning with a space followed by a shell-quoted 76 # version of the argument. 77 # Two strategies: enclose in single quotes if it contains none; 78 # otherwise, enclose in double quotes and prefix quotable characters 79 # with backslash. 80 # 81 def mkarg(x): 82 if '\'' not in x: 83 return ' \'' + x + '\'' 84 s = ' "' 85 for c in x: 86 if c in '\\$"`': 87 s = s + '\\' 88 s = s + c 89 s = s + '"' 90 return s 91
