[SOLVED] bash: Can't split string at colon (pure bash)

L_Carver · 11-21-2018, 12:55 PM

Here's another basic thing I've forgotten how to do: split a string and return the first part at a delimiter (in this case a colon :).

My code (scriptname: getfilenames.sh)

Code:

tg="$1"

while IFS=":" read -r y
do
echo "${y%%*:}"
done < "$tg"
echo "${y%%*:}"
done < "$tg"

stdout returns, on an example file (see attachment):

Code:

bash getfilenames.sh theunders
038_1000.jpg:Underwater Wonders
167_1000.jpg:Underwater Wonders
501_1000.jpg:Underwater Wonders
732_1000.jpg:Underwater Wonders
her-job-intrvu.jpg:Underwater Wonders
ihre-tag-im-ozean.jpg:Underwater Wonders
suf-261-919-015.jpg:Underwater Wonders
suf-699-136-133.jpg:Underwater Wonders
suf-791-432-188.jpg:Underwater Wonders
suf-936-891-544.jpg:Underwater Wonders
suf-996-295-145.jpg:Underwater Wonders

What I want it to return is

038_1000.jpg
167_1000.jpg
501_1000.jpg
732_1000.jpg
her-job-intrvu.jpg
ihre-tag-im-ozean.jpg
suf-261-919-015.jpg
suf-699-136-133.jpg
suf-791-432-188.jpg
suf-936-891-544.jpg
suf-996-295-145.jpg

How do I get there, in pure BASH. I want to get away from using cut, but I'm on the verge of resorting to it if I can't find an "internal" work-around.

Carver.

BW-userx · 11-21-2018, 01:12 PM

Quote:

Originally Posted by L_Carver

Here's another basic thing I've forgotten how to do: split a string and return the first part at a delimiter (in this case a colon :).

My code (scriptname: getfilenames.sh)

Code:

tg="$1"

while IFS=":" read -r y
do
echo "${y%%*:}"
done < "$tg"
echo "${y%%*:}"
done < "$tg"

your * (star) is on the wrong side.

Code:

$ go="732_1000.jpg:Underwater Wonders"
$ g=${go%:*}
$ echo $g
732_1000.jpg

$ o=${go#*:}
$ echo $o
Underwater Wonders

michaelk · 11-21-2018, 04:11 PM

You need to specify both variables in your read statement.

Code:

#!/bin/bash

while IFS=":" read -r y z
do
echo $y
done < "theunders.txt"

There are many ways to manipulate strings.

L_Carver · 12-02-2018, 12:09 PM

@michaelk:

That looks like the best way to do it. Besides, it brings back one of my favourite things to do in bash: declare field separators.

Thanks a bunch.

Carver
[Thread closed.]