How Can I Efficiently Pipe External Command Outputs in Python's `subprocess` Module?

Execute External Commands with Pipes Using subprocess

When working with the subprocess module, it may be necessary to use pipes to connect the output of one external command as the input to another. To achieve this, you can utilize the shell=True parameter in the subprocess.check_output() function.

However, it is crucial to proceed with caution when using shell=True due to security concerns. Instead, it is recommended to create separate processes for each command and pipe the output accordingly.

To elaborate further, consider the following example:

ps = subprocess.Popen(('ps', '-A'), stdout=subprocess.PIPE)
output = subprocess.check_output(('grep', 'process_name'), stdin=ps.stdout)
ps.wait()

In this scenario, the ps command is executed, and its output is piped into the grep command. The resulting output from grep is then stored in the 'output' variable.

Alternatively, if shell=True is not desired, you can utilize str.find to achieve the same result:

output = subprocess.check_output(('ps', '-A'))
process_found = 'process_name' in output

The above is the detailed content of How Can I Efficiently Pipe External Command Outputs in Python's `subprocess` Module?. For more information, please follow other related articles on the PHP Chinese website!