diff options
| -rw-r--r-- | Lib/commands.py | 64 |
1 files changed, 44 insertions, 20 deletions
diff --git a/Lib/commands.py b/Lib/commands.py index 6471a8d..567248e 100644 --- a/Lib/commands.py +++ b/Lib/commands.py @@ -1,3 +1,24 @@ +"""Execute shell commands via os.popen() and return status, output. + +Interface summary: + + import commands + + outtext = commands.getoutput(cmd) + (exitstatus, outtext) = commands.getstatusoutput(cmd) + outtext = commands.getstatus(file) # returns output of "ls -ld file" + +A trailing newline is removed from the output string. + +Encapsulates the basic operation: + + pipe = os.popen('{ ' + cmd + '; } 2>&1', 'r') + text = pipe.read() + sts = pipe.close() + + [Note: it would be nice to add functions to interpret the exit status.] +""" + # Module 'commands' # # Various tools for executing commands and looking at their output and status. @@ -8,7 +29,8 @@ # Get 'ls -l' status for an object into a string # def getstatus(file): - return getoutput('ls -ld' + mkarg(file)) + """Return output of "ls -ld <file>" in a string.""" + return getoutput('ls -ld' + mkarg(file)) # Get the output from a shell command into a string. @@ -16,27 +38,29 @@ def getstatus(file): # Assume the command will work with '{ ... ; } 2>&1' around it.. # def getoutput(cmd): - return getstatusoutput(cmd)[1] + """Return output (stdout or stderr) of executing cmd in a shell.""" + return getstatusoutput(cmd)[1] # Ditto but preserving the exit status. # Returns a pair (sts, output) # def getstatusoutput(cmd): - import os - pipe = os.popen('{ ' + cmd + '; } 2>&1', 'r') - text = pipe.read() - sts = pipe.close() - if sts == None: sts = 0 - if text[-1:] == '\n': text = text[:-1] - return sts, text + """Return (status, output) of executing cmd in a shell.""" + import os + pipe = os.popen('{ ' + cmd + '; } 2>&1', 'r') + text = pipe.read() + sts = pipe.close() + if sts == None: sts = 0 + if text[-1:] == '\n': text = text[:-1] + return sts, text # Make command argument from directory and pathname (prefix space, add quotes). # def mk2arg(head, x): - import os - return mkarg(os.path.join(head, x)) + import os + return mkarg(os.path.join(head, x)) # Make a shell command argument from a string. @@ -47,12 +71,12 @@ def mk2arg(head, x): # 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 + if '\'' not in x: + return ' \'' + x + '\'' + s = ' "' + for c in x: + if c in '\\$"`': + s = s + '\\' + s = s + c + s = s + '"' + return s |