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#!/usr/bin/env python
"""
exec_command
Implements exec_command function that is (almost) equivalent to
commands.getstatusoutput function but on NT, DOS systems the
returned status is actually correct (though, the returned status
values may be different by a factor). In addition, exec_command
takes keyword arguments for (re-)defining environment variables.
Provides functions:
exec_command --- execute command in a specified directory and
in the modified environment.
find_executable --- locate a command using info from environment
variable PATH. Equivalent to posix `which`
command.
Author: Pearu Peterson <pearu@cens.ioc.ee>
Created: 11 January 2003
Requires: Python 2.x
Succesfully tested on:
os.name | sys.platform | comments
--------+--------------+----------
posix | linux2 | Debian (sid) Linux, Python 2.1.3+, 2.2.3+, 2.3.3
PyCrust 0.9.3, Idle 1.0.2
posix | linux2 | Red Hat 9 Linux, Python 2.1.3, 2.2.2, 2.3.2
posix | sunos5 | SunOS 5.9, Python 2.2, 2.3.2
posix | darwin | Darwin 7.2.0, Python 2.3
nt | win32 | Windows Me
Python 2.3(EE), Idle 1.0, PyCrust 0.7.2
Python 2.1.1 Idle 0.8
nt | win32 | Windows 98, Python 2.1.1. Idle 0.8
nt | win32 | Cygwin 98-4.10, Python 2.1.1(MSC) - echo tests
fail i.e. redefining environment variables may
not work. FIXED: don't use cygwin echo!
Comment: also `cmd /c echo` will not work
but redefining environment variables do work.
posix | cygwin | Cygwin 98-4.10, Python 2.3.3(cygming special)
nt | win32 | Windows XP, Python 2.3.3
Known bugs:
- Tests, that send messages to stderr, fail when executed from MSYS prompt
because the messages are lost at some point.
"""
__all__ = ['exec_command','find_executable']
import os
import sys
import shlex
from numpy.distutils.misc_util import is_sequence, make_temp_file
from numpy.distutils import log
def temp_file_name():
fo, name = make_temp_file()
fo.close()
return name
def get_pythonexe():
pythonexe = sys.executable
if os.name in ['nt','dos']:
fdir,fn = os.path.split(pythonexe)
fn = fn.upper().replace('PYTHONW','PYTHON')
pythonexe = os.path.join(fdir,fn)
assert os.path.isfile(pythonexe), '%r is not a file' % (pythonexe,)
return pythonexe
def splitcmdline(line):
import warnings
warnings.warn('splitcmdline is deprecated; use shlex.split',
DeprecationWarning)
return shlex.split(line)
def find_executable(exe, path=None, _cache={}):
"""Return full path of a executable or None.
Symbolic links are not followed.
"""
key = exe, path
try:
return _cache[key]
except KeyError:
pass
log.debug('find_executable(%r)' % exe)
orig_exe = exe
if path is None:
path = os.environ.get('PATH',os.defpath)
if os.name=='posix':
realpath = os.path.realpath
else:
realpath = lambda a:a
if exe.startswith('"'):
exe = exe[1:-1]
suffixes = ['']
if os.name in ['nt','dos','os2']:
fn,ext = os.path.splitext(exe)
extra_suffixes = ['.exe','.com','.bat']
if ext.lower() not in extra_suffixes:
suffixes = extra_suffixes
if os.path.isabs(exe):
paths = ['']
else:
paths = [ os.path.abspath(p) for p in path.split(os.pathsep) ]
for path in paths:
fn = os.path.join(path, exe)
for s in suffixes:
f_ext = fn+s
if not os.path.islink(f_ext):
f_ext = realpath(f_ext)
if os.path.isfile(f_ext) and os.access(f_ext, os.X_OK):
log.good('Found executable %s' % f_ext)
_cache[key] = f_ext
return f_ext
log.warn('Could not locate executable %s' % orig_exe)
return None
############################################################
def _preserve_environment( names ):
log.debug('_preserve_environment(%r)' % (names))
env = {}
for name in names:
env[name] = os.environ.get(name)
return env
def _update_environment( **env ):
log.debug('_update_environment(...)')
for name,value in env.items():
os.environ[name] = value or ''
def exec_command( command,
execute_in='', use_shell=None, use_tee = None,
_with_python = 1,
**env ):
""" Return (status,output) of executed command.
command is a concatenated string of executable and arguments.
The output contains both stdout and stderr messages.
The following special keyword arguments can be used:
use_shell - execute `sh -c command`
use_tee - pipe the output of command through tee
execute_in - before run command `cd execute_in` and after `cd -`.
On NT, DOS systems the returned status is correct for external commands.
Wild cards will not work for non-posix systems or when use_shell=0.
"""
log.debug('exec_command(%r,%s)' % (command,\
','.join(['%s=%r'%kv for kv in env.items()])))
if use_tee is None:
use_tee = os.name=='posix'
if use_shell is None:
use_shell = os.name=='posix'
execute_in = os.path.abspath(execute_in)
oldcwd = os.path.abspath(os.getcwd())
if __name__[-12:] == 'exec_command':
exec_dir = os.path.dirname(os.path.abspath(__file__))
elif os.path.isfile('exec_command.py'):
exec_dir = os.path.abspath('.')
else:
exec_dir = os.path.abspath(sys.argv[0])
if os.path.isfile(exec_dir):
exec_dir = os.path.dirname(exec_dir)
if oldcwd!=execute_in:
os.chdir(execute_in)
log.debug('New cwd: %s' % execute_in)
else:
log.debug('Retaining cwd: %s' % oldcwd)
oldenv = _preserve_environment( env.keys() )
_update_environment( **env )
try:
# _exec_command is robust but slow, it relies on
# usable sys.std*.fileno() descriptors. If they
# are bad (like in win32 Idle, PyCrust environments)
# then _exec_command_python (even slower)
# will be used as a last resort.
#
# _exec_command_posix uses os.system and is faster
# but not on all platforms os.system will return
# a correct status.
if _with_python and (0 or sys.__stdout__.fileno()==-1):
st = _exec_command_python(command,
exec_command_dir = exec_dir,
**env)
elif os.name=='posix':
st = _exec_command_posix(command,
use_shell=use_shell,
use_tee=use_tee,
**env)
else:
st = _exec_command(command, use_shell=use_shell,
use_tee=use_tee,**env)
finally:
if oldcwd!=execute_in:
os.chdir(oldcwd)
log.debug('Restored cwd to %s' % oldcwd)
_update_environment(**oldenv)
return st
def _exec_command_posix( command,
use_shell = None,
use_tee = None,
**env ):
log.debug('_exec_command_posix(...)')
if is_sequence(command):
command_str = ' '.join(list(command))
else:
command_str = command
tmpfile = temp_file_name()
stsfile = None
if use_tee:
stsfile = temp_file_name()
filter = ''
if use_tee == 2:
filter = r'| tr -cd "\n" | tr "\n" "."; echo'
command_posix = '( %s ; echo $? > %s ) 2>&1 | tee %s %s'\
% (command_str,stsfile,tmpfile,filter)
else:
stsfile = temp_file_name()
command_posix = '( %s ; echo $? > %s ) > %s 2>&1'\
% (command_str,stsfile,tmpfile)
#command_posix = '( %s ) > %s 2>&1' % (command_str,tmpfile)
log.debug('Running os.system(%r)' % (command_posix))
status = os.system(command_posix)
if use_tee:
if status:
# if command_tee fails then fall back to robust exec_command
log.warn('_exec_command_posix failed (status=%s)' % status)
return _exec_command(command, use_shell=use_shell, **env)
if stsfile is not None:
f = open(stsfile,'r')
status_text = f.read()
status = int(status_text)
f.close()
os.remove(stsfile)
f = open(tmpfile,'r')
text = f.read()
f.close()
os.remove(tmpfile)
if text[-1:]=='\n':
text = text[:-1]
return status, text
def _exec_command_python(command,
exec_command_dir='', **env):
log.debug('_exec_command_python(...)')
python_exe = get_pythonexe()
cmdfile = temp_file_name()
stsfile = temp_file_name()
outfile = temp_file_name()
f = open(cmdfile,'w')
f.write('import os\n')
f.write('import sys\n')
f.write('sys.path.insert(0,%r)\n' % (exec_command_dir))
f.write('from exec_command import exec_command\n')
f.write('del sys.path[0]\n')
f.write('cmd = %r\n' % command)
f.write('os.environ = %r\n' % (os.environ))
f.write('s,o = exec_command(cmd, _with_python=0, **%r)\n' % (env))
f.write('f=open(%r,"w")\nf.write(str(s))\nf.close()\n' % (stsfile))
f.write('f=open(%r,"w")\nf.write(o)\nf.close()\n' % (outfile))
f.close()
cmd = '%s %s' % (python_exe, cmdfile)
status = os.system(cmd)
if status:
raise RuntimeError("%r failed" % (cmd,))
os.remove(cmdfile)
f = open(stsfile,'r')
status = int(f.read())
f.close()
os.remove(stsfile)
f = open(outfile,'r')
text = f.read()
f.close()
os.remove(outfile)
return status, text
def quote_arg(arg):
if arg[0]!='"' and ' ' in arg:
return '"%s"' % arg
return arg
def _exec_command( command, use_shell=None, use_tee = None, **env ):
log.debug('_exec_command(...)')
if use_shell is None:
use_shell = os.name=='posix'
if use_tee is None:
use_tee = os.name=='posix'
using_command = 0
if use_shell:
# We use shell (unless use_shell==0) so that wildcards can be
# used.
sh = os.environ.get('SHELL','/bin/sh')
if is_sequence(command):
argv = [sh,'-c',' '.join(list(command))]
else:
argv = [sh,'-c',command]
else:
# On NT, DOS we avoid using command.com as it's exit status is
# not related to the exit status of a command.
if is_sequence(command):
argv = command[:]
else:
argv = shlex.split(command)
if hasattr(os,'spawnvpe'):
spawn_command = os.spawnvpe
else:
spawn_command = os.spawnve
argv[0] = find_executable(argv[0]) or argv[0]
if not os.path.isfile(argv[0]):
log.warn('Executable %s does not exist' % (argv[0]))
if os.name in ['nt','dos']:
# argv[0] might be internal command
argv = [os.environ['COMSPEC'],'/C'] + argv
using_command = 1
# sys.__std*__ is used instead of sys.std* because environments
# like IDLE, PyCrust, etc overwrite sys.std* commands.
so_fileno = sys.__stdout__.fileno()
se_fileno = sys.__stderr__.fileno()
so_flush = sys.__stdout__.flush
se_flush = sys.__stderr__.flush
so_dup = os.dup(so_fileno)
se_dup = os.dup(se_fileno)
outfile = temp_file_name()
fout = open(outfile,'w')
if using_command:
errfile = temp_file_name()
ferr = open(errfile,'w')
log.debug('Running %s(%s,%r,%r,os.environ)' \
% (spawn_command.__name__,os.P_WAIT,argv[0],argv))
argv0 = argv[0]
if not using_command:
argv[0] = quote_arg(argv0)
so_flush()
se_flush()
os.dup2(fout.fileno(),so_fileno)
if using_command:
#XXX: disabled for now as it does not work from cmd under win32.
# Tests fail on msys
os.dup2(ferr.fileno(),se_fileno)
else:
os.dup2(fout.fileno(),se_fileno)
try:
status = spawn_command(os.P_WAIT,argv0,argv,os.environ)
except OSError,errmess:
status = 999
sys.stderr.write('%s: %s'%(errmess,argv[0]))
so_flush()
se_flush()
os.dup2(so_dup,so_fileno)
os.dup2(se_dup,se_fileno)
fout.close()
fout = open(outfile,'r')
text = fout.read()
fout.close()
os.remove(outfile)
if using_command:
ferr.close()
ferr = open(errfile,'r')
errmess = ferr.read()
ferr.close()
os.remove(errfile)
if errmess and not status:
# Not sure how to handle the case where errmess
# contains only warning messages and that should
# not be treated as errors.
#status = 998
if text:
text = text + '\n'
#text = '%sCOMMAND %r FAILED: %s' %(text,command,errmess)
text = text + errmess
print errmess
if text[-1:]=='\n':
text = text[:-1]
if status is None:
status = 0
if use_tee:
print text
return status, text
def test_nt(**kws):
pythonexe = get_pythonexe()
echo = find_executable('echo')
using_cygwin_echo = echo != 'echo'
if using_cygwin_echo:
log.warn('Using cygwin echo in win32 environment is not supported')
s,o=exec_command(pythonexe\
+' -c "import os;print os.environ.get(\'AAA\',\'\')"')
assert s==0 and o=='',(s,o)
s,o=exec_command(pythonexe\
+' -c "import os;print os.environ.get(\'AAA\')"',
AAA='Tere')
assert s==0 and o=='Tere',(s,o)
os.environ['BBB'] = 'Hi'
s,o=exec_command(pythonexe\
+' -c "import os;print os.environ.get(\'BBB\',\'\')"')
assert s==0 and o=='Hi',(s,o)
s,o=exec_command(pythonexe\
+' -c "import os;print os.environ.get(\'BBB\',\'\')"',
BBB='Hey')
assert s==0 and o=='Hey',(s,o)
s,o=exec_command(pythonexe\
+' -c "import os;print os.environ.get(\'BBB\',\'\')"')
assert s==0 and o=='Hi',(s,o)
elif 0:
s,o=exec_command('echo Hello')
assert s==0 and o=='Hello',(s,o)
s,o=exec_command('echo a%AAA%')
assert s==0 and o=='a',(s,o)
s,o=exec_command('echo a%AAA%',AAA='Tere')
assert s==0 and o=='aTere',(s,o)
os.environ['BBB'] = 'Hi'
s,o=exec_command('echo a%BBB%')
assert s==0 and o=='aHi',(s,o)
s,o=exec_command('echo a%BBB%',BBB='Hey')
assert s==0 and o=='aHey', (s,o)
s,o=exec_command('echo a%BBB%')
assert s==0 and o=='aHi',(s,o)
s,o=exec_command('this_is_not_a_command')
assert s and o!='',(s,o)
s,o=exec_command('type not_existing_file')
assert s and o!='',(s,o)
s,o=exec_command('echo path=%path%')
assert s==0 and o!='',(s,o)
s,o=exec_command('%s -c "import sys;sys.stderr.write(sys.platform)"' \
% pythonexe)
assert s==0 and o=='win32',(s,o)
s,o=exec_command('%s -c "raise \'Ignore me.\'"' % pythonexe)
assert s==1 and o,(s,o)
s,o=exec_command('%s -c "import sys;sys.stderr.write(\'0\');sys.stderr.write(\'1\');sys.stderr.write(\'2\')"'\
% pythonexe)
assert s==0 and o=='012',(s,o)
s,o=exec_command('%s -c "import sys;sys.exit(15)"' % pythonexe)
assert s==15 and o=='',(s,o)
s,o=exec_command('%s -c "print \'Heipa\'"' % pythonexe)
assert s==0 and o=='Heipa',(s,o)
print 'ok'
def test_posix(**kws):
s,o=exec_command("echo Hello",**kws)
assert s==0 and o=='Hello',(s,o)
s,o=exec_command('echo $AAA',**kws)
assert s==0 and o=='',(s,o)
s,o=exec_command('echo "$AAA"',AAA='Tere',**kws)
assert s==0 and o=='Tere',(s,o)
s,o=exec_command('echo "$AAA"',**kws)
assert s==0 and o=='',(s,o)
os.environ['BBB'] = 'Hi'
s,o=exec_command('echo "$BBB"',**kws)
assert s==0 and o=='Hi',(s,o)
s,o=exec_command('echo "$BBB"',BBB='Hey',**kws)
assert s==0 and o=='Hey',(s,o)
s,o=exec_command('echo "$BBB"',**kws)
assert s==0 and o=='Hi',(s,o)
s,o=exec_command('this_is_not_a_command',**kws)
assert s!=0 and o!='',(s,o)
s,o=exec_command('echo path=$PATH',**kws)
assert s==0 and o!='',(s,o)
s,o=exec_command('python -c "import sys,os;sys.stderr.write(os.name)"',**kws)
assert s==0 and o=='posix',(s,o)
s,o=exec_command('python -c "raise \'Ignore me.\'"',**kws)
assert s==1 and o,(s,o)
s,o=exec_command('python -c "import sys;sys.stderr.write(\'0\');sys.stderr.write(\'1\');sys.stderr.write(\'2\')"',**kws)
assert s==0 and o=='012',(s,o)
s,o=exec_command('python -c "import sys;sys.exit(15)"',**kws)
assert s==15 and o=='',(s,o)
s,o=exec_command('python -c "print \'Heipa\'"',**kws)
assert s==0 and o=='Heipa',(s,o)
print 'ok'
def test_execute_in(**kws):
pythonexe = get_pythonexe()
tmpfile = temp_file_name()
fn = os.path.basename(tmpfile)
tmpdir = os.path.dirname(tmpfile)
f = open(tmpfile,'w')
f.write('Hello')
f.close()
s,o = exec_command('%s -c "print \'Ignore the following IOError:\','\
'open(%r,\'r\')"' % (pythonexe,fn),**kws)
assert s and o!='',(s,o)
s,o = exec_command('%s -c "print open(%r,\'r\').read()"' % (pythonexe,fn),
execute_in = tmpdir,**kws)
assert s==0 and o=='Hello',(s,o)
os.remove(tmpfile)
print 'ok'
def test_svn(**kws):
s,o = exec_command(['svn','status'],**kws)
assert s,(s,o)
print 'svn ok'
def test_cl(**kws):
if os.name=='nt':
s,o = exec_command(['cl','/V'],**kws)
assert s,(s,o)
print 'cl ok'
if os.name=='posix':
test = test_posix
elif os.name in ['nt','dos']:
test = test_nt
else:
raise NotImplementedError,'exec_command tests for '+os.name
############################################################
if __name__ == "__main__":
test(use_tee=0)
test(use_tee=1)
test_execute_in(use_tee=0)
test_execute_in(use_tee=1)
test_svn(use_tee=1)
test_cl(use_tee=1)
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