CODEWITHSUNDEEP
regexlinuxstringbashsed
Deep Blue
Deep Blue

Reputation: 303

Insert a character 4 chars before end of string in BASH

Is there a way to insert a colon 4 chars before the end of a string? For example, I have 0x2aab3f439000 and I need 0x2aab3f43:9000

Thanks

Upvotes: 3

Views: 4818

Answers (5)

Sylvain Leroux
Sylvain Leroux

Reputation: 52030

An other pure bash answer:

sh$ V=0x2aab3f439000
sh$ echo ${V::(-4)}:${V:(-4)}
0x2aab3f43:9000

Upvotes: 1

Cyrus
Cyrus

Reputation: 88776

a=0x2aab3f439000

echo ${a:0:-4}:${a#${a:0:-4}}

Output:

0x2aab3f43:9000

Upvotes: 1

Etan Reisner
Etan Reisner

Reputation: 81012

$ s=0x2aab3f439000
$ echo "${s:0:(${#s}-4)}:${s:(-4)}"
0x2aab3f43:9000

Alternative (from glenn jackman):

echo "${s%????}:${s: -4}"

Upvotes: 5

Parthian Shot
Parthian Shot

Reputation: 1432

RESULT="$( \
    echo -n $ORIG | head -c $(( $(echo -n "$ORIG" | wc -c) - 4)) && \
    echo -n : && \
    echo -n $ORIG | tail -c 4 \
)"

Proof of concept:

me@ ~$ ORIG="hello world"
me@ ~$ RESULT="$( \
>     echo -n $ORIG | head -c $(( $(echo -n "$ORIG" | wc -c) - 4)) && \
>     echo -n : && \
>     echo -n $ORIG | tail -c 4 \
> )"
me@ ~$ echo "$RESULT"
hello w:orld

There are certainly more elegant ways of doing this, but it's hard to beat this for clarity.

Upvotes: 0

anubhava
anubhava

Reputation: 785611

Using sed you can do:

s='0x2aab3f439000'
sed 's/.\{4\}$/:&/' <<< "$s"
0x2aab3f43:9000

Upvotes: 8

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