how to get a piece of text in bash

Byenary · 12-14-2006, 09:32 AM

#!/bin/sh
TEXT = this is a piec of text formed bij a formail instruction

I need an instruction to grab the first 4 characters from the text, anybody knows it ?

Wells · 12-14-2006, 09:39 AM

The way I read this, you are trying to pull the word "this" from that text string. One way to do this is with awk:

#!/bin/sh
TEXT = this is a piece of text formed by a formall instruction
FIRSTWORD = `echo $TEXT | awk {'print $1'}`

echo $FIRSTWORD

ghostdog74 · 12-14-2006, 10:09 AM

in bash, you can do string manipulation

eg

echo ${TEXT:0:4}

see http://www.faqs.org/docs/abs/HTML/st...ipulation.html
for more

matthewg42 · 12-14-2006, 12:50 PM

There are several ways:

Code:

#!/bin/bash

TEXT="This is my test string"
echo "using awk:                        $(echo "$TEXT" |awk '{ print $1 }')"
echo "using perl:                       $(echo "$TEXT" | perl -ne 's/ .*$//; print;')"
echo "using cut:                        $(echo "$TEXT" |cut -d' ' -f1)"
echo "using sed:                        $(echo "$TEXT" |sed 's/ .*//')"
echo "using expr (need to know length): $(expr substr "$TEXT" 1 4)"

# These are faster since there is no external program invocation:
echo "using shell suffix removal:       ${TEXT%% *}"
echo "using bash's substring expansion: ${TEXT:0:4}"

Byenary · 12-14-2006, 02:09 PM

In my case the substring looks like the best solution, thx for the support !!