bash vs perl vs python

keceli · 07-18-2007, 12:19 PM

I am a beginner, and want to learn which language is better for file editing purposes.

Particularly what i am looking for is to read some numbers (or strings) from a file "A" (taking the largest n numbers or the numbers in certain lines or a certain string) and then insert them into a specific part of another file "B". (I need to replace a text in file "B")

As far as i know perl is good for string manipulations, but if it could be done by bash scripts, maybe that's easier.

indienick · 07-18-2007, 01:46 PM

I would suggest Perl for that.
Perl = Practical Extraction and Reporting Language
That sort of stuff can get messy with Bash.

pixellany · 07-18-2007, 02:15 PM

I would also look at Python...

Disclosure: I am not a programmer. I do have a working knowledge of C, and have most recently started learning Python. There is something about the simplicity of Python that is quite appealling--and the tutorial on the official site is among the best I have ever seen.

Any of the 3 will work--bash scripting is maybe the hardest to learn.

bigearsbilly · 07-19-2007, 03:24 AM

shell scripting is good for simple, general admin at whole file and directory level
but when you start cutting up files and playing with them, it rapidly
runs out of power.

perl and python are both great languages,
perl is more ubiquitous on a range of unix machines, python prettier
and more elegant.

ghostdog74 · 07-19-2007, 03:46 AM

Quote:

Originally Posted by keceli

I am a beginner, and want to learn which language is better for file editing purposes.

Particularly what i am looking for is to read some numbers (or strings) from a file "A" (taking the largest n numbers or the numbers in certain lines or a certain string) and then insert them into a specific part of another file "B". (I need to replace a text in file "B")

As far as i know perl is good for string manipulations, but if it could be done by bash scripts, maybe that's easier.

if you want to stick to shell, awk and sed are the next most suitable tools you can use.

bigearsbilly · 07-19-2007, 04:07 AM

hmm,
at risk of a flame war,

sed and awk are pretty much subsets of perl
now.
sed is still useful sometimes but only for one-liners.

ghostdog74 · 07-19-2007, 04:23 AM

Quote:

Originally Posted by bigearsbilly

hmm,
at risk of a flame war,

sed and awk are pretty much subsets of perl
now.

i agree, however let's stick to what OP wants, file editing, getting some text in file A and replace with text in file B. This task can be done with just shell tools, all depending on the OP's choice of tools of course. If he wants to use Perl then by all means.

Quote:

sed is still useful sometimes but only for one-liners.

not true. If you read the recent "debate" on sed on a previous thread, sed is turing complete, so it can do more than just one-liners, albeit more "tedious" to code to perform certain tasks.

keceli · 07-19-2007, 11:38 PM

thanks all, I used perl, the following commands were very useful,
@array=fileAhandle #writes all file line by line to array
print fileBhandle @newarrayB #writes the new array to file

iwasapenguin · 07-20-2007, 12:21 AM

I know less than I should about half-a-dozen or so languages so I'm not the perfect person to give advice but my rule of thumb is to program in the language made for your job. In this case perl, python is good as a learning tool and can be used to extend the functions of a lot of programms, shell scripts are for linking to gether the utilities on the shell.

rizhun · 07-20-2007, 09:35 AM

Concidering you are a beginner and the task you are trying to accomplish, Perl is the obvious winner.

Get yourself the 'Learning Perl' O'Reilly book - it's very good.

Once you have mastered Perl you won't have any trouble picking up most other languages.

iwasapenguin · 07-23-2007, 08:21 PM

For that matter typing man -k perl into your terminal will bring up a good list of manuals on perl that cover pretty much everything.

chrism01 · 07-23-2007, 10:57 PM

Here is the motherlode for Perl; includes lang def with examples, plus tutorials and more.
http://perldoc.perl.org/