Top-rated recipes tagged "commandline"

Unix tee-like functionality via a Python class (Python)

2017-03-31T14:30:30-07:00

Python recipe 580767 by Vasudev Ram (cli, command, commandline, linux, python, tee, unix, utilities, windows).

The Unix tee commmand, when used in a command pipeline, allows you to capture the output of the preceding command to a file or files, while still sending it on to standard output (stdout) for further processing via other commands in a pipeline, or to print it, etc.

This recipe shows how to implement simple tee-like functionality via a Python class. I do not aim to exactly replicate the functionality of the Unix tee, only something similar.

More details and sample output here:

https://jugad2.blogspot.in/2017/03/a-python-class-like-unix-tee-command.html

Simple command-line alarm clock in Python (Python)

2015-10-25T18:27:27-07:00

Python recipe 579117 by Vasudev Ram (alarm, clock, commandline, linux, python, time, unix, windows).

This recipe shows how to create a simple alarm clock in Python, that can be run from the command line in a terminal. It lets you specify the alarm time in minutes as a command line argument, and prints a wake-up message and beeps a few times, after that time arrives. You can use 0 for the minutes to test it immediately, including to adjust the volume using your speaker controls.

argdeclare: declarative interface to argparse (Python)

2010-03-02T00:05:40-08:00

Python recipe 576935 by Shakeeb Alireza (argparse, cmdln, commandline, getopt, metaclass, option). Revision 5.

This is an implementation of the interface provided by the cmdln module but using argparse to provide the option/arg heavy parsing.

An example of usage is provided in the test function, which should produce the following from the command line:

$ python argdeclare.py --help

usage: argdeclare.py [-h] [-v] {uninstall,install,delete} ...

a description of the test app

optional arguments:
  -h, --help            show this help message and exit
  -v, --version         show program's version number and exit

subcommands:
  valid subcommands

  {uninstall,install,delete}
                        additional help
    delete              help text for delete subcmd
    install             help text for install subcmd
    uninstall           help text for uninstall subcmd

$ python argdeclare.py install --help

usage: argdeclare.py install [-h] [-t TYPE] [--log] [-f] package

positional arguments:
  package               package to be (un)installed

optional arguments:
  -h, --help            show this help message and exit
  -t TYPE, --type TYPE  specify type of package
  --log, -l             log is on
  -f, --force           force through installation

enjoy!

Show OS error codes and messages from the os.errno module (Python)

2017-03-01T17:18:23-08:00

Python recipe 580759 by Vasudev Ram (commandline, introspection, libraries, python, unix, utilities, windows).

This recipe is a simple Python introspection utility that displays the defined OS error codes and messages (that Python knows about) from the os.errno module. It works for both Python 2 and Python 3. For each kind of OS error defined in Python, it will display a serial number, the error code, and the corresponding error name, and English error message. E.g. the first few lines of its output are shown below:

$ py -2 os_errno_info.py

Showing error codes and names

from the os.errno module:

Python sys.version: 2.7.12

Number of error codes: 86

Idx Code Name Message

0 1 EPERM Operation not permitted

1 2 ENOENT No such file or directory

2 3 ESRCH No such process

3 4 EINTR Interrupted function call

4 5 EIO Input/output error

More information, full output and other details are available here:

https://jugad2.blogspot.in/2017/03/show-error-numbers-and-codes-from.html

A simple text file pager in Python (Python)

2017-02-10T21:34:45-08:00

Python recipe 580755 by Vasudev Ram (command, commandline, pagination, paging, python, text, utilities, windows).

This recipe shows how to create a simple text file pager in Python. It allows you to view text content a page at a time (with a user-definable number of lines per page). Like standard Unix utilities, it can either take a text file name as a command-line argument, or can read the text from its standard input, which can be redirected to come from a file, or to come from a pipe. The recipe is for Windows only, though, since it uses the msvcrt.getch() function, which is Windows-specific. However, the recipe can be modified to work on Unix by using things like tty, curses, termios, cbreak, etc.

More details here:

https://jugad2.blogspot.in/2017/02/tp-simple-text-pager-in-python.html

A utility like Unix seq (command-line), in Python (Python)

2017-01-08T17:48:57-08:00

Python recipe 580744 by Vasudev Ram (bash, command, commandline, linux, script, seq, sequence, shell, unix, utilities, utility).

This recipe shows how to create a utility like Unix seq (command-line), in Python. seq is described here:

https://en.wikipedia.org/wiki/Seq_(Unix)

but briefly, it is a command-line utility that takes 1 to 3 arguments (some being optional), the start, stop and step, and prints numbers from the start value to the stop value, on standard output. So seq has many uses in bigger commands or scripts; a common category of use is to quickly generate multiple filenames or other strings that contain numbers in them, for exhaustive testing, load testing or other purposes. A similar command called jot is found on some Unix systems.

This recipe does not try to be exactly the same in functionality as seq. It has some differences. However the core functionality of generating integer sequences is the same (but without steps other than 1 for the range).

More details and sample output are here:

https://jugad2.blogspot.in/2017/01/an-unix-seq-like-utility-in-python.html

The code is below.

Give Python code a web plus command-line interface with hug (Python)

2017-01-05T16:57:15-08:00

Python recipe 580742 by Vasudev Ram (cli, commandline, hug, library, python, python3, user_interface, web, web_server).

This recipe shows how to take a Python function and wrap it with both a web and a command-line interface, somewhat easily, using the hug Python library. The example used shows how to wrap a function that uses the psutil library to get information on disk partitions. So you can see the disk partition info either via the web browser or the command line. The code for the recipe is shown below. It is also possible to wrap multiple functions in the same Python file, and expose all of them via both the web and the command-line.

More information and multiple sample outputs are available here:

https://jugad2.blogspot.in/2017/01/give-your-python-function-webcli-hug.html

[xtopdf] Publish Delimiter-Separated Values (DSV data) to PDF (Python)

2016-12-17T19:08:33-08:00

Python recipe 580736 by Vasudev Ram (commandline, csv, data, files, formats, pdf, pdf_generation, python, tsv, utilities, xtopdf).

This recipe shows how to publish delimiter-separated values (a commonly used tabular data format) to PDF, using the xtopdf toolkit for PDF creation. It lets the user specify the delimiter via one of two command-line options - an ASCII code or an ASCII character. As Unix filters tend to do, it can operate either on standard input or on input filenames given as command-line arguments. In the case of multiple inputs via files, each input goes to a separate PDF output file.

Simple directory list command with filename wildcard support (Python)

2016-12-02T20:52:56-08:00

Python recipe 580724 by Vasudev Ram (commandline, directory, file, filesystem, python, utilities).

This recipe shows a simple directory listing program. It can accept multiple command-line arguments specifying filenames. These filenames can include wildcard characters like * (asterisk) and ? (question mark), as is common in OS command shells like bash (Unix) and CMD (Windows). Tested on Windows but should work on Unix too, since it uses no OS-specific functions, or rather, it does use them, but that happens under the hood, within the libraries used.

Process Delimiter-Separated Values data with Python (Python)

2016-11-24T23:57:35-08:00

Python recipe 580722 by Vasudev Ram (command, commandline, data, dsv, file, python, utilities, utility).

This recipe shows how to read and process delimiter-separated values (DSV) data with a Python command-line program. It provides two ways of specifying the delimiter character, by an ASCII character or an ASCII code, which makes it more flexible than allowing only a character. It allows the DSV data to be specified as one or more filenames on the command line, or given via the standard input of the program.

'Which' for Windows (Python)

2013-08-16T09:14:07-07:00

Python recipe 578642 by Robert Pyron (commandline, python, utility, which, windows). Revision 2.

WHICH.PY scans through all directories specified in the system %PATH% environment variable, looking for the specified COMMAND(s). It tries to follow the sometimes bizarre rules for Windows command lookup.

download a URL with a console progress meter (Python)

2008-10-08T05:05:12-07:00

Python recipe 576530 by Trent Mick (commandline, download, url).

A little script/function to download a given URL with a console progress meter. Usage:

python geturl.py http://example.com/downloads/bigfile.zip

(This is from an old post to python-list.)

Text ruler for console (record-oriented data processing utility) (Python)

2016-04-17T19:32:26-07:00

Python recipe 580647 by Vasudev Ram (commandline, python, rulers, unix, utilities, windows).

This recipe shows how to create a simple text-based ruler for your command-line console. It can help you find the position of your own program's output on the line, or to find the positions and lengths of fields in fixed- or variable-length records in a text file, fields in CSV files, etc.

A binary file split utility in Python (Python)

2016-04-07T18:19:35-07:00

Python recipe 580637 by Vasudev Ram (binary, commandline, linux, python, unix, utility, windows).

This recipe shows how to create a simple binary file split utility in Python.

It takes two command line arguments: 1) the name of the input file to split , 2) the number of bytes per file into which to split the input.

File comparison utility in Python (Python)

2016-03-26T18:31:11-07:00

Python recipe 580631 by Vasudev Ram (commandline, comparison, file, files, linux, python, unix, utilities).

This is a recipe to compare any two files via a Python command-line program. It is like a basic version of the cmp command of Unix or the fc.exe (file compare) command of Windows.

Unix-like split command in Python (simple version) (Python)

2016-03-14T22:35:05-07:00

Python recipe 580620 by Vasudev Ram (commandline, linux, python, shell, split, splitting, unix, utilities, utility, windows).

This recipe shows how to create a simple version of the Unix split command in Python. The split command splits an input file into multiple smaller files, the size of each of which is specified by a command-line argument giving the number of lines per file. This is useful for multiple purposes, such as editing large files in pieces, backing up files to small capacity storage devices, sending files across the network, etc.

A UNIX-like "which" command for Python (Python)

2015-03-20T19:23:45-07:00

Python recipe 579035 by Vasudev Ram (bash, commandline, commands, linux, shell, unix, utilities, which).

UNIX users are familiar with the which command. Given an argument called name, it checks the system PATH environment variable, to see whether that name exists (as a file) in any of the directories specified in the PATH. (The directories in the PATH are colon-separated on UNIX and semicolon-separated on Windows.)

This recipe shows how to write a minimal which command in Python. It has been tested on Windows.

beep based alarm - command line utility (Python)

2014-10-25T22:29:10-07:00

Python recipe 578953 by Tomas Nordin (alarm, argparse, beep, commandline). Revision 2.

An alarm beeping on you when the eggs are boiled.

Better quote module for bash shells (Python)

2010-12-03T09:16:45-08:00

Python recipe 577483 by Kevin L. Sitze (bash, command, commandline, escape, logging, quote, script, shell).

This Python module quotes a Python string so that it will be treated as a single argument to commands ran via os.system() (assuming bash is the underlying shell). In other words, this module makes arbitrary strings "command line safe" (for bash command lines anyway, YMMV if you're using Windows or one of the (less fine) posix shells).

Create PDF at the end of a Unix pipeline with PDFWriter (Python)

2013-12-22T22:19:00-08:00

Python recipe 578794 by Vasudev Ram (commandline, linux, pdf, pipelining, reportlab, unix, xtopdf).

This recipe shows how to create PDF output at the end of a Unix or Linux pipeline, after all the text processing required, is done by previous components of the pipeline (which can use any of the standard tools of Unix such as sed, grep, awk, etc., as well as custom programs that act as filters).