exec – Page 7 – Tarik Billa

How to invoke external command from within Kotlin code?

January 7, 2023 by Tarik

Example of running a git diff by shelling out: “git diff”.runCommand(gitRepoDir) Here are two implementations of the runCommand extension function: 1. Redirect to stdout/stderr This wires any output from the subprocess to regular stdout and stderr: fun String.runCommand(workingDir: File) { ProcessBuilder(*split(” “).toTypedArray()) .directory(workingDir) .redirectOutput(Redirect.INHERIT) .redirectError(Redirect.INHERIT) .start() .waitFor(60, TimeUnit.MINUTES) } 2. Capturing output as a String … Read more

Why does find -exec mv {} ./target/ + not work?

January 3, 2023 by Tarik

The manual page (or the online GNU manual) pretty much explains everything. find -exec command {} \; For each result, command {} is executed. All occurences of {} are replaced by the filename. ; is prefixed with a slash to prevent the shell from interpreting it. find -exec command {} + Each result is appended … Read more

What are the different versions of exec used for in C and C++?

January 3, 2023 by Tarik

The differences are combinations of: L vs V: whether you want to pass the parameters to the exec’ed program as L: individual parameters in the call (variable argument list): execl(), execle(), execlp(), and execlpe() V: as an array of char* execv(), execve(), execvp(), and execvpe() The array format is useful when the number of parameters … Read more

difference between docker attach and docker exec

January 2, 2023 by Tarik

2015: There was a commit PR which added to the doc: Note: This command (attach) is not for running a new process in a container. See: docker exec. The answer to “Docker. How to get bash\ssh inside runned container (run -d)?” illustrates the difference: (docker >= 1.3) If we use docker attach, we can use … Read more

How to execute file I’m editing in Vi(m)

December 28, 2022 by Tarik

There is the make command. It runs the command set in the makeprg option. Use % as a placeholder for the current file name. For example, if you were editing a python script: :set makeprg=python\ % Yes, you need to escape the space. After this you can simply run: :make If you wish, you can … Read more

How to make pipes work with Runtime.exec()?

December 23, 2022 by Tarik

Write a script, and execute the script instead of separate commands. Pipe is a part of the shell, so you can also do something like this: String[] cmd = { “/bin/sh”, “-c”, “ls /etc | grep release” }; Process p = Runtime.getRuntime().exec(cmd);

Running a Python script from PHP

November 29, 2022 by Tarik

Tested on Ubuntu Server 10.04. I hope it helps you also on Arch Linux. In PHP use shell_exec function: Execute command via shell and return the complete output as a string. It returns the output from the executed command or NULL if an error occurred or the command produces no output. <?php $command = escapeshellcmd(‘/usr/custom/test.py’); … Read more

How to execute an external program from within Node.js?

November 20, 2022 by Tarik

var exec = require(‘child_process’).exec; exec(‘pwd’, function callback(error, stdout, stderr) { // result });

node.js execute system command synchronously

October 16, 2022 by Tarik

Node.js (since version 0.12 – so for a while) supports execSync: child_process.execSync(command[, options]) You can now directly do this: const execSync = require(‘child_process’).execSync; code = execSync(‘node -v’); and it’ll do what you expect. (Defaults to pipe the i/o results to the parent process). Note that you can also spawnSync now.

Differences between fork and exec

October 10, 2022 by Tarik

The use of fork and exec exemplifies the spirit of UNIX in that it provides a very simple way to start new processes. The fork call basically makes a duplicate of the current process, identical in almost every way. Not everything is copied over (for example, resource limits in some implementations) but the idea is … Read more