RE: how to change os.popen4 to subprocess
Replying to skyworld because I could not find the original message from MRAB. skyworld wrote: > On Oct 27, 11:02 am, MRAB wrote: > > On 2012-10-27 03:28, skyworld wrote:> Hi, > > > > > I'm new to python and I'm trying to porting some scripts from v0.96 to > > > v2.0.1. A piece of code is like this: > > > > > cmd_h = os.popen4(env['SYSCMDLINE'])[1] > > > > > the system indicates the popen4 is deprecated and suggest to use > > > subprocess. Can anybody tell me how to use subprocess in this case? > > > and what does "[1]" here means? > > > > os.popen4 returns a tuple of (child_stdin, child_stdout_and_stderr). > > The [1] gets the child_stdout_and_stderr member. > > > > Using the subprocess module: > > > > # Untested! > > cmd_h = subprocess.Popen(env['SYSCMDLINE'], stdout=subprocess.PIPE, > > stderr=subprocess.STDOUT, shell=True).stdout > > > > Explanation: > > > > The command line: env['SYSCMDLINE'] > > > > Return stdout: stdout=subprocess.PIPE > > > > stderr should be combined with stdout: stderr=subprocess.STDOUT > > > > Let the shell parse the command line: shell=True > > thanks > -- I thought the usage of shell=True is usually discouraged? The subprocess documentation[0] should be helpful to figure it out. """ Warning: Invoking the system shell with shell=True can be a security hazard if combined with untrusted input. See the warning under Frequently Used Arguments for details. """ [0] http://docs.python.org/2/library/subprocess.html Ramit This email is confidential and subject to important disclaimers and conditions including on offers for the purchase or sale of securities, accuracy and completeness of information, viruses, confidentiality, legal privilege, and legal entity disclaimers, available at http://www.jpmorgan.com/pages/disclosures/email. -- http://mail.python.org/mailman/listinfo/python-list
Re: how to change os.popen4 to subprocess
On Oct 27, 11:02 am, MRAB wrote: > On 2012-10-27 03:28, skyworld wrote:> Hi, > > > I'm new to python and I'm trying to porting some scripts from v0.96 to > > v2.0.1. A piece of code is like this: > > > cmd_h = os.popen4(env['SYSCMDLINE'])[1] > > > the system indicates the popen4 is deprecated and suggest to use > > subprocess. Can anybody tell me how to use subprocess in this case? > > and what does "[1]" here means? > > os.popen4 returns a tuple of (child_stdin, child_stdout_and_stderr). > The [1] gets the child_stdout_and_stderr member. > > Using the subprocess module: > > # Untested! > cmd_h = subprocess.Popen(env['SYSCMDLINE'], stdout=subprocess.PIPE, > stderr=subprocess.STDOUT, shell=True).stdout > > Explanation: > > The command line: env['SYSCMDLINE'] > > Return stdout: stdout=subprocess.PIPE > > stderr should be combined with stdout: stderr=subprocess.STDOUT > > Let the shell parse the command line: shell=True thanks -- http://mail.python.org/mailman/listinfo/python-list
Re: how to change os.popen4 to subprocess
On 27/10/2012 03:28, skyworld wrote: Hi, I'm new to python and I'm trying to porting some scripts from v0.96 to v2.0.1. A piece of code is like this: What software are you talking about here, it's certainly not Python versions as the most up to date are 2.7.3 and 3.3.0? cmd_h = os.popen4(env['SYSCMDLINE'])[1] the system indicates the popen4 is deprecated and suggest to use subprocess. Can anybody tell me how to use subprocess in this case? and what does "[1]" here means? If you don't know what the [1] means you've got problems :) I suggest you read the tutorial here first http://docs.python.org/tutorial/index.html then the subprocess module here http://docs.python.org/library/subprocess.html#module-subprocess, specifically http://docs.python.org/library/subprocess.html#subprocess-replacements thanks. No problem. -- Cheers. Mark Lawrence. -- http://mail.python.org/mailman/listinfo/python-list
Re: how to change os.popen4 to subprocess
On 2012-10-27 03:28, skyworld wrote: Hi, I'm new to python and I'm trying to porting some scripts from v0.96 to v2.0.1. A piece of code is like this: cmd_h = os.popen4(env['SYSCMDLINE'])[1] the system indicates the popen4 is deprecated and suggest to use subprocess. Can anybody tell me how to use subprocess in this case? and what does "[1]" here means? os.popen4 returns a tuple of (child_stdin, child_stdout_and_stderr). The [1] gets the child_stdout_and_stderr member. Using the subprocess module: # Untested! cmd_h = subprocess.Popen(env['SYSCMDLINE'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT, shell=True).stdout Explanation: The command line: env['SYSCMDLINE'] Return stdout: stdout=subprocess.PIPE stderr should be combined with stdout: stderr=subprocess.STDOUT Let the shell parse the command line: shell=True -- http://mail.python.org/mailman/listinfo/python-list
