CODEWITHSUNDEEP
regexunix
Hyph
Hyph

Reputation:

Unix - substitution

i have problem with substitution. I have a file with 1 line of random characters with brackets "{}" around 1 character. I want to move with these brackets on the previous character or on the next one. (I know how to do it if the line of character is still, non-changing.) But I wonder how to do it when I don't know these chars and I don't know where these brackets are.

For Example: " ABC123{X}CBA321 " ==> " ABC12{3}XCBA321 " or " ABC123X{C}BA321 "

I would like to use awk or sed, some regex, maybe...

Upvotes: 1

Views: 249

Answers (4)

Gopal SA
Gopal SA

Reputation: 959

I tried in perl. this will move the bracket to the previous character

my $a="ABC123{X}CBA321";

if ($a =~ /(.)\{(.)\}/)
        {
                print "$`"."{$1}";
                print "$2";
                print "$'";
        }

NOTE: $` is string before the match & $' is string after match

Upvotes: 0

strager
strager

Reputation: 90012

Move backward one character:

sed -e 's/\(.\){\(.\)}/{\1}\2/g' file

Move forward one character:

sed -e 's/{\(.\)}\(.\)/\1{\2}/g' file

To modify the file in-place, use the -i flag:

sed -i -e 's/\(.\){\(.\)}/{\1}\2/g' file
sed -i -e 's/{\(.\)}\(.\)/\1{\2}/g' file

The first example works by matching any character followed by a character surrounded by {}. Without grouping, this is: .{.} We add grouping so we can put the two characters in the output. Instead of surrounding the second character with {} with surround the first character. This is {\1}\2.

The second example works similarly, but matches {.}. first then outputs \1{\2}.

Upvotes: 5

ashawley
ashawley

Reputation: 4283

Here's a small example.

$ echo "ABC123{X}CBA321" | sed -e 's/\(.\){\(.\)}\(.\)/{\1}\2\3/'
ABC12{3}XCBA321
$ echo "ABC123{X}CBA321" | sed -e 's/\(.\){\(.\)}\(.\)/\1\2{\3}/'
ABC123X{C}BA321

Here's how to edit the file in place with sed.

$ sed -i -e 's/\(.\){\(.\)}\(.\)/{\1}\2\3/' file
$ sed -i -e 's/\(.\){\(.\)}\(.\)/\1\2{\3}/' file

Upvotes: 1

davr
davr

Reputation: 19137

This will move the brackets to the previous character:

sed -e 's/\(.\){\(.\)}/{\1}\2/g' < in_file > out_file

This will move the brackets to the next character:

sed -e 's/{\(.\)}\(.\)/\1{\2}/g' < in_file > out_file

Upvotes: 3

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