Bash: Pulling first and last character in string Post: 302962326

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Top Forums Shell Programming and Scripting Bash: Pulling first and last character in string Post 302962326 by durden_tyler on Friday 11th of December 2015 08:14:07 PM

12-11-2015

Registered User

Sure, you're welcome!
If you have never programmed in Perl, then it might take some time to become comfortable with the language. But if you're going to do complex file processing, then learning a scripting language (any language: awk, Perl, Python, Ruby etc.) might be a good investment of your time.

A good way to learn Perl would be to start small and understand one concept at a time. For example,
- the shebang line (first line)
- the purpose of "use strict"
- hashes, arrays, scalars,
- how files are read, how they are written
- regular expression syntax
- functions like "lc", "int"
- operators like "defined" etc.

The Perl documentation is the best place to get information about these individual bits:
(1) perldoc.perl.org

Simon Cozen's online book is good for understanding programming in Perl (only the first 6 chapters should be enough):
(2) https://www.perl.org/books/beginning-perl/

The books by O'Reilly are well regarded:
(3) Learning Perl
(4) Intermediate Perl

And for the advanced Perl programmer:
(5) Programming Perl

Cookbooks are very interesting as well - they provide just enough information to get the job done. An online Perl cookbook is:
(6) PLEAC-Perl

And the published book is:
(7) Perl Cookbook, 2nd edition

This website has a list of Perl tutorials on the Internet and also mentions which ones are good and which ones are bad:
(8) Perl Tutorial Hub

However, besides reading about Perl, you'll also need to actually write programs to understand it.

=================

Having said that, there should be other forum members here who could post awk or plain Bash scripts for your problem, so keep an eye on this space.

Last edited by durden_tyler; 12-11-2015 at 09:20 PM..

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LEARN ABOUT X11R4

libbash

LIBBASH(7)							  libbash Manual							LIBBASH(7)

NAME

     libbash -- A bash shared libraries package.

DESCRIPTION

     libbash  is  a package that enables bash dynamic-like shared libraries. Actually its a tool for managing bash scripts whose functions you may
     want to load and use in scripts of your own.

     It contains a 'dynamic loader' for the shared libraries ( ldbash(1)), a configuration tool (ldbashconfig(8)), and some libraries.

     Using ldbash(1) you are able to load loadable bash libraries, such as getopts(1) and hashstash(1).  A bash shared library that can be  loaded
     using
     ldbash(1) must answer 4 requirments:

     1.     It must be installed in $LIBBASH_PREFIX/lib/bash (default is /usr/lib/bash).

     2.     It must contain a line that begins with '#EXPORT='.  That line will contain (after the '=') a list of functions that the library
	    exports.  I.e. all the function that will be usable after loading that library will be listed in that line.

     3.     It must contain a line that begins with '#REQUIRE='.  That line will contain (after the '=') a list of bash libraries that are
	    required for our library.  I.e. every bash library that is in use in our bash library must be listed there.

     4.     The library must be listed (For more information, see ldbashconfig(8)).

   Basic guidelines for writing library of your own:
     1.     Be aware, that your library will be actually sourced. So, basically, it should contain (i.e define) only functions.

     2.     Try to declare all variables intended for internal use as local.

     3.     Global variables and functions that are intended for internal use (i.e are not defined in '#EXPORT=') should begin with:
		  __<library_name>_
	    For example, internal function myfoosort of hashstash library should be named as
		  __hashstash_myfoosort
	    This helps to avoid conflicts in global name space when using libraries that come from different vendors.

     4.     See html manual for full version of this guide.

AUTHORS

     Hai Zaar <haizaar@haizaar.com>
     Gil Ran <ril@ran4.net>

SEE ALSO

     ldbash(1), ldbashconfig(8), getopts(1), hashstash(1) colors(1) messages(1) urlcoding(1) locks(1)

Linux								       Epoch								     Linux

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