Bash script to create a header for Bash scripts (Bash)

2011-11-02T01:57:07-07:00

Bash recipe 577862 by userend (auto, bash, create, emacs, gpl, header, linux, script, shell, vim). Revision 3.

This will create a header for a Bash script. It is a nice way keep a track of what your script does and when it was created, the author of the script, etc..

It will open the script automatically with one of the two most popular editor out there, Vim or Emacs! It also checks to see if there is a script with the same name in the current working directory so it will not overwrite another file.

v0.4: I had to kick this up a notch. I took the suggestion of "dev h" to add a chance for the user to select another name for the script.

Please leave comments and suggestions.

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.

Line-oriented processing in Python from command line (like AWK) (Python)

2011-04-14T19:49:16-07:00

Python recipe 577656 by Artur Siekielski (awk, bash, python, shell).

A very simple but powerful shell script which enables writing ad-hoc Python scripts for processing line-oriented input. It executes the following code template:

$INIT
for line in sys.stdin:
    $LOOP
$END

where $INIT, $LOOP and $END code blocks are given from command line. If only one argument is given, then $INIT and $END are empty. If two arguments are given, $END is empty.

Examples (script is saved as 'pyk' in the $PATH):

"wc -l" replacement: $ cat file | pyk 'c=0' 'c+=1' 'print c'
grep replacement: $ cat file | pyk 'import re' 'if re.search("\d+", line): print line'
adding all numbers: $ seq 1 10 | pyk 's=0' 's+=int(line)' 'print s'
prepending lines with it's length: $ cat file | pyk 'print len(line), line'
longest file name: $ ls -1 | pyk 'longest=""' 'if len(line) > len(longest): longest=line' 'print longest'
number of unique words in a document: $ pyk 'words=[]' 'words.extend(line.split())' 'print "All words: {}, unique: {}".format(len(words), len(set(words))'

touch (Python)

2009-09-28T16:19:23-07:00

Python recipe 576915 by Trent Mick (file, shell, touch, unix).

Python function a la the Unix touch program (man touch).

A Shell, Binary To Hexadecimal To Decimal Demo... (Bash)

2013-01-11T18:31:03-08:00

Bash recipe 578413 by Barry Walker (apple, bash, binary, decimal, demo, hexadecimal, linux, macbook_pro, shell, terminal).

This little DEMO may be common knowledge to the big guns but not to amateurs like myself, so......

This is an Apple Macbbok Shell/Terminal DEMO shell script to show how to:-

1) Create a binary file... 2) Save it to your DEFAULT /directory/drwawer/folder/... 3) Display a hexadecimal dump of said binary file to prove that it is binary... 4) Select a single BYTE of that file and save it as an ASCII text decimal _number_, also to your DEFAULT /directory/drawer/folder/... 5) Read this ASCII text decimal number back in again... 6) Add this string representation to a number... 7) Stop...

It was intended purely for OSX 10.7.5 and above using the default terminal and shell...

It does work on many Linux flavours and shells/terminals also however.

Written so the anyone can understand what is going on.

The two files generated and saved in this DEMO to your DEFAULT /directory/drawer/folder/ are:-

BinaryString.dat BinaryString.txt

This WILL lead to something very unusual in the not too distant future...

This is Public Domain and you may do with it as you wish...

Enjoy finding simple solutions to often very difficult problems...

Bazza, G0LCU...

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).

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.

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.

Bash Prompt Rainbow Color Chart (Bash)

2011-10-02T21:39:21-07:00

Bash recipe 577889 by userend (bash, color, prompt, ps1, rainbow, shell, terminal).

This is a simple loop that displays a rainbow of different colors.

Simple invocation of shell commands (Python)

2011-10-21T06:44:35-07:00

Python recipe 577891 by Nick Coghlan (processes, shell). Revision 3.

Some simple wrappers around the subprocess functions for use in system administration utilities that frequently need to interpolate trusted data into shell commands (e.g. filenames from directory listings, etc):

import shellcmd
return_code = shellcmd.shell_call('ls -l {}', dirname)
listing = shellcmd.check_shell_output('ls -l {}', dirname)

Each function invokes the subprocess function of the same name with shell=True and the supplied command string. Any positional and keyword arguments provided to the call are interpolated into the command string with the str.format method.

Coloured / highlighted version of string (Python)

2014-06-03T17:54:33-07:00

Python recipe 577818 by Giampaolo Rodolà (color, debugging, highlighting, shell). Revision 3.

Ok, this is really simple but I think it worths a recipe as it's one of those things I always use in shell scripts and for debugging in general.

A Building Block, Bash Binary File Manipulation... (Bash)

2013-01-29T22:07:57-08:00

Bash recipe 578441 by Barry Walker (apple, bash, binary, linux, macbook_pro, script, shell). Revision 2.

Apologies for any typos, and IF this has been done before...

The code generates a 256 byte binary file of _characters_ 0x00 to 0xFF for general usage and generates another binary file manipulated in a basic way.

The for loops in the code are purely for DEMO purposes only.

This is Public Domain and you may do with it as you please. I have uploaded it elsewhere too...

Watch for wordwrapping, etc and read the code for more information...

Enjoy finding simple solutions to often very difficult problems...

Bazza, G0LCU...

Teach the hashbang header new tricks using a dual mode shell/python script (Python)

2011-08-21T07:27:05-07:00

Python recipe 577851 by Oren Tirosh (hashbang, interpreter, options, python, sh, shell).

This dual-mode script is both a Posix shell script and a python script. The shell part looks like a triple-quoted string to the Python interpreter. The shell does not reach anything after the exec statement.

Print selected text pages to PDF with Python, selpg and xtopdf on Linux (Bash)

2014-10-29T17:38:10-07:00

Bash recipe 578954 by Vasudev Ram (bash, linux, pdf, python, reportlab, shell, text, text_files, text_processing, unix).

This recipe shows how to use selpg, a Linux command-line utility written in C, together with xtopdf, a Python toolkit for PDF creation, to print only a selected range of pages from a text file, to a PDF file, for display or print purposes. The way to do this is to run the selpg utility at the Linux command line, with options specifying the start and end pages of the range, and pipe its output to the StdinToPDF.py program, which is a part of the xtopdf toolkit.

Git Shell Script to enhance inline automation script... (Bash)

2010-11-01T00:43:03-07:00

Bash recipe 577447 by Patrick Riendeau (code, concurrency, git, oop, oriented, programs, property, property_creation, repository, shell, shelve).

This tiny effort, depend from Fnct.D ActiveState no.577446 Core, also available from github http://github.com/priendeau/Fnct.d, can develop basic methodology of implementing oriented program within uses of function re-declaration with function-parser to create both property-function to discover uses of getter-function and setter-function

Arduino Diecimila Board Access Inside A Linux Bash Shell. (Text)

2011-03-30T18:08:11-07:00

Text recipe 577627 by Barry Walker (access, arduino, bash, linux, shell, text).

The "code" in this recipe is a step by step "root" shell command line procedure for testing whether a(n) USB Arduino Dev Board is working or not. To get more recognisable characters displayed it is best to use a potentiometer wired as one end to +5V, the other end to Gnd and thw wiper to ANALOG IN 0. This has been tested on various Linux Distros and kept as simple as possible so that anyone can understand it.

The required ?.pde file for the Arduino Board can be found here:-

http://code.activestate.com/recipes/577625-arduino-diecimila-board-access-inside-winuae-demo/?in=lang-python

It is issued entirely as Public Domain by B.Walker, G0LCU, 30-03-2011, and you may do with it as you please.

Similar assumptions are made as in the URL above.

Enjoy finding simple solutions to often very difficult problems... ;o)

A simple shell script to keep the wife off of your back... (Bash)

2013-12-09T20:05:49-08:00

Bash recipe 578781 by Barry Walker (apple, bash, linux, macbook_pro, reminder, script, shell).

How many times have you been asked to remember to do something from the other half whilst she is out for a short while.

For example: "You WILL check the dinner every few minutes won't you?"

And how many times did/do you forget?

Most of us have been there...

This is a simple kids level, practical learning, shell script that generates an "xterm" with your reminder inside every 30 seconds for a period of 3 seconds.

It is always be the active front window for 3 seconds at a time to _annoy_ you into remembering.

Usage: reminder "What you have to remember here using spaces AND double quotes."<CR>

Just reanme the downloaded script to reminder and remember to chmod it as required.

Just run it from your default terminal and when finished press Ctrl-C just AFTER the xterm window closes.

There is NO error detection so steer clear of any special characters in you reminder text.

Enjoy finding simple solutions to often very difficult problems...

DEMO - Generate A Crude 1KHz Sinewave Using A BASH Script. (Bash)

2013-03-01T19:41:47-08:00

Bash recipe 578477 by Barry Walker (audio, bash, demo, generator, linux, shell, sinewave, sound).

A very simple crude sinewave generator using a BASH script inside a Linux Terminal.

The file required is generated inside the code and requires /dev/audio to work.

Ensure you have this device, if not the download oss-compat from your OS's repository...

It lasts for about 8 seconds before exiting and saves a 65536 byte file to your working directory/drawer/folder as sinewave.raw.

Use an oscilloscope to check the waveform generated...

It is entirely Public Domain and you may do with it as you please...

Enjoy finding simple solutions to often very difficult problems... ;o)

Bazza, G0LCU...

Pass The FizzBuzz Test (Bash)

2011-11-02T00:26:45-07:00

Bash recipe 577938 by userend (bash, buzz, fizz, fizzbuzz, job, math, script, shell).

This is my version of the FizzBuzz test.

Fnct.D, comprehensive Bash-shell coding scheme. (Bash)

2010-11-01T00:29:09-07:00

Bash recipe 577446 by Patrick Riendeau (bash, object, oop, oriented, shell, system).

A Bash compromising shell-module to pre-introduce object-oriented Bash-code.

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