[SOLVED] Script

business_kid · 02-19-2023, 12:46 PM

Code:

for i in *.xxx;
  do name=`echo "$i" | cut -d'.' -f1

This script segment preserves everything up to the first '.' and cuts the rest. It fails when there's more than 1 dot in the filename.

That, however is the wrong way around for me, as some files have numerous dots. How would I cut from the other end? For example, how would I cut the '.xxx' fromn a file like 'long.silly.file.name.xxx'

Input: long.silly.file.name.xxx
Desired output: long.silly.file.name

TIA

pan64 · 02-19-2023, 01:06 PM

At first, this title is meaningless, would be nice to use a meaningful one. See man bash and parameter expansion, especially ${var##.*} and ${var%*} and friends https://www.gnu.org/software/bash/ma...eter-Expansion

michaelk · 02-19-2023, 01:06 PM

What about string manipulation?

Code:

name=${i%.xxx}

Not fast enough...

lvm_ · 02-19-2023, 01:06 PM

gawk 'BEGIN{FS=".";OFS=FS}{NF--;print}'

MadeInGermany · 02-19-2023, 01:07 PM

cut is an external command, and has no means to address fields from the end.
Two reasons for a variable modifier:

Code:

name=${i%.*}

% deletes from the end, minimal expansion of wildcards.

%% does the same but greedy expansion of wildcards i.e. would delete till the leftmost dot.

wpeckham · 02-19-2023, 01:47 PM

I second MadeInGermany. There is no reason to work in a shell unless you plan to use the power of the shell. If your shell is BASH, you have some powerful built-in string processing, so use it.
(Same can be said of KSH, ZSH, and some of the other shells but they may offer different options and implemented differently.)

computersavvy · 02-19-2023, 09:07 PM

If you know the extension, as seems you want to strip only that part, then you could also use the basename command to get everything but the extension part.

Examples in the manpage

Code:

       basename include/stdio.h .h
              -> "stdio"

       basename -s .h include/stdio.h
              -> "stdio"

rnturn · 02-19-2023, 10:50 PM

Quote:

Originally Posted by business_kid

Code:

for i in *.xxx;
  do name=`echo "$i" | cut -d'.' -f1

This script segment preserves everything up to the first '.' and cuts the rest. It fails when there's more than 1 dot in the filename.

That, however is the wrong way around for me, as some files have numerous dots. How would I cut from the other end? For example, how would I cut the '.xxx' fromn a file like 'long.silly.file.name.xxx'

Input: long.silly.file.name.xxx
Desired output: long.silly.file.name

TIA

Play around with

Code:

$ echo "aa.bb.cc.dd.xxx" | sed 's/.xxx$//'

I think it'll help you.

JJJCR · 02-20-2023, 03:25 AM

Agree with MadeInGermany, you can do like this:

Quote:

a='long.silly.file.name.xxx'
echo "${a%.*}"
"." <-- remove suffix starting this char

hazel · 02-20-2023, 04:27 AM

Why not use the rev command?

business_kid · 02-20-2023, 05:55 AM

Wow! First time I looked at this there was 10 replies. Thanks guys. And sorry, there was a word missing out of the subject.

Thanks to all, and kudos to MadeInGermany who was first in with a very elegant solution which has just been implemented and has completed it's first working run.

Along with all the half baked & useless tripe they had modules on in my hardware degree, you'd think they'd have time for an essential skill like scripting.

syg00 · 02-20-2023, 06:01 AM

It should be noted (by the OP) that bash (note shell specific) features are continually added. They likely didn't exist when you were a squeaky voiced student.

Some call it bloat ... :shrug:

wpeckham · 02-20-2023, 12:15 PM

Quote:

Originally Posted by syg00

It should be noted (by the OP) that bash (note shell specific) features are continually added. They likely didn't exist when you were a squeaky voiced student.

Some call it bloat ... :shrug:

When I was a student BASH had not been written yet. Those man pages are worth gold, when they are well written and current. Search engines and the people who have put examples of new features and using them properly on the internet: priceless!

business_kid · 02-20-2023, 02:10 PM

Quote:

Originally Posted by syg00

It should be noted (by the OP) that bash (note shell specific) features are continually added. They likely didn't exist when you were a squeaky voiced student.

Some call it bloat ... :shrug:

No squeaky voice as a student here.
I didn't get my degree until my kids were grown - I was turning into an old fart

Every job offered for me after I closed my business needed a degree, so I decided to get one. What with my wife getting sick, and getting a year chopped out of my degree midstream(!) it proved to be a forgettable experience. In fact, the lecturers learned nearly as much from me as I did from them.

I graduated with a degree more suited to the last millenium in 2014, and had a stroke the next year

.