CODEWITHSUNDEEP
bashshellawksed
prabodhprakash
prabodhprakash

Reputation: 3927

Shell script to convert a string from one form to another

I have two strings

internal func add(a: Int, b: Int) -> Int
add(a:b:)

How can I make the first string convert into the second string. I can do this in programming languages, but unable to figure out a solution for bash script that I need.

Essentially whats needed is anything before (and including) func should be trimmed and anything following (and including) -> should be removed and the type of variables should be removed. All spaces should also go.

Also, I tried using regex. I made (?:.*func\s(.*)\s->.*) that takes out the add(a: Int, b: Int) from the 1st string, but, I am not sure, how to further eliminate this string.

I preferably need some help in bash using awk or sed but regex would also do well for me.

Upvotes: 1

Views: 466

Answers (4)

Marek Nowaczyk
Marek Nowaczyk

Reputation: 257

This is another sed approach to problem:

sed -r 's/^.*internal func *(\w+)\(([^)]*)\).*$/\1(\2)/;ta;b;:a;s/*(\w+:) *\w+,*/\1/g'

Upvotes: -2

Inian
Inian

Reputation: 85800

A solution in perl regEx as

perl -lne 'print "$1$2$3)" if /^.*func (\w+)(\(\w+:).*, (\w+:).*\).*$/ ' <<<"internal func add(a: Int, b: Int) -> Int"
add(a:b:)

where, $1, $2 and $3 are the capturing groups and a small hack with printing ) at end.

If your shell does not support here-strings(<<<), just do 

echo "internal func add(a: Int, b: Int) -> Int" | perl -lne 'print "$1$2$3)" if /^.*func (\w+)(\(\w+:).*, (\w+:).*\).*$/ ' 
add(a:b:)

Upvotes: 1

OscarAkaElvis
OscarAkaElvis

Reputation: 5714

Using pure bash in "oneliner" style:

#!/bin/bash
str="internal func add(a: Int, b: Int) -> Int"
[[ $str =~ .*func[[:space:]](.*\(.*:).*,[[:space:]]?(.*:).*(\)) ]] && str="${BASH_REMATCH[1]}${BASH_REMATCH[2]}${BASH_REMATCH[3]}"
echo $str

It works even if the string doesn't have the space after the comma which seems optional.

Upvotes: 3

Ruslan Osmanov
Ruslan Osmanov

Reputation: 21502

Using SED:

string='internal func add(a: Int, b: Int) -> Int'

sed -e '
s/^.*func \+//
s/ *\->.*$//
s/:[^,)]\+/:/g
s/[, ]//g
' <<< "$string"
  • s/^.*func \+// removes the front (^) part before func, func, and spaces after func;
  • s/ *\->.*$// removes spaces followed by -> and anything after it at the end of the string;
  • s/:[^,)]\+/:/g removes the type names after colons;
  • s/[, ]//g performs final cleanup by removing commas and spaces.

Upvotes: 2

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