diff options
Diffstat (limited to 'Lib/subprocess.py')
| -rw-r--r-- | Lib/subprocess.py | 76 |
1 files changed, 73 insertions, 3 deletions
diff --git a/Lib/subprocess.py b/Lib/subprocess.py index d39eb19..ba4fac0 100644 --- a/Lib/subprocess.py +++ b/Lib/subprocess.py @@ -17,7 +17,6 @@ intends to replace several other, older modules and functions, like: os.system os.spawn* -commands.* Information about how the subprocess module can be used to replace these modules and functions can be found below. @@ -105,7 +104,7 @@ appearance of the main window and priority for the new process. (Windows only) -This module also defines two shortcut functions: +This module also defines four shortcut functions: call(*popenargs, **kwargs): Run command with arguments. Wait for command to complete, then @@ -125,6 +124,34 @@ check_call(*popenargs, **kwargs): check_call(["ls", "-l"]) +getstatusoutput(cmd): + Return (status, output) of executing cmd in a shell. + + Execute the string 'cmd' in a shell with os.popen() and return a 2-tuple + (status, output). cmd is actually run as '{ cmd ; } 2>&1', so that the + returned output will contain output or error messages. A trailing newline + is stripped from the output. The exit status for the command can be + interpreted according to the rules for the C function wait(). Example: + + >>> import subprocess + >>> subprocess.getstatusoutput('ls /bin/ls') + (0, '/bin/ls') + >>> subprocess.getstatusoutput('cat /bin/junk') + (256, 'cat: /bin/junk: No such file or directory') + >>> subprocess.getstatusoutput('/bin/junk') + (256, 'sh: /bin/junk: not found') + +getoutput(cmd): + Return output (stdout or stderr) of executing cmd in a shell. + + Like getstatusoutput(), except the exit status is ignored and the return + value is a string containing the command's output. Example: + + >>> import subprocess + >>> subprocess.getoutput('ls /bin/ls') + '/bin/ls' + + Exceptions ---------- Exceptions raised in the child process, before the new program has @@ -336,7 +363,8 @@ else: import fcntl import pickle -__all__ = ["Popen", "PIPE", "STDOUT", "call", "check_call", "CalledProcessError"] +__all__ = ["Popen", "PIPE", "STDOUT", "call", "check_call", "getstatusoutput", + "getoutput", "CalledProcessError"] try: MAXFD = os.sysconf("SC_OPEN_MAX") @@ -458,6 +486,48 @@ def list2cmdline(seq): return ''.join(result) +# Various tools for executing commands and looking at their output and status. +# +# NB This only works (and is only relevant) for UNIX. + +def getstatusoutput(cmd): + """Return (status, output) of executing cmd in a shell. + + Execute the string 'cmd' in a shell with os.popen() and return a 2-tuple + (status, output). cmd is actually run as '{ cmd ; } 2>&1', so that the + returned output will contain output or error messages. A trailing newline + is stripped from the output. The exit status for the command can be + interpreted according to the rules for the C function wait(). Example: + + >>> import subprocess + >>> subprocess.getstatusoutput('ls /bin/ls') + (0, '/bin/ls') + >>> subprocess.getstatusoutput('cat /bin/junk') + (256, 'cat: /bin/junk: No such file or directory') + >>> subprocess.getstatusoutput('/bin/junk') + (256, 'sh: /bin/junk: not found') + """ + pipe = os.popen('{ ' + cmd + '; } 2>&1', 'r') + text = pipe.read() + sts = pipe.close() + if sts is None: sts = 0 + if text[-1:] == '\n': text = text[:-1] + return sts, text + + +def getoutput(cmd): + """Return output (stdout or stderr) of executing cmd in a shell. + + Like getstatusoutput(), except the exit status is ignored and the return + value is a string containing the command's output. Example: + + >>> import subprocess + >>> subprocess.getoutput('ls /bin/ls') + '/bin/ls' + """ + return getstatusoutput(cmd)[1] + + class Popen(object): def __init__(self, args, bufsize=0, executable=None, stdin=None, stdout=None, stderr=None, |