Shell script to manipulate if loop

Question

I am trying to modify a if loop in a large code base.My need is as follows.

The code may contain as follows.This is just a random combination example of an if condition.I need to modify if else if conditions alone.

if((A==B)&&(C==D)&&((E==F)||(G==H))||(I)&&(J!=K))

should be modified as

 if((string.Compare(A,B)==0)&&(string.Compare(C,D)==0)&&((string.Compare(E,F)==0)||(string.Compare(G,H)==0))||(I)&&(string.Compare(J,K)!=0))

I tried with Java but utterly failed.I believe this is possible with sed or awk.Any help?

-1 The question is really unclear. You should put some effort if you want to be understood. Don't just blame others. — Rajish
– Rajish, Commented May 10, 2011 at 8:10
I am sorry if my question was not clear.I will upvote your answer so that it does not affect your reputation. — Harish
– Harish, Commented May 10, 2011 at 9:19

Oscar Mederos · Accepted Answer · 2011-05-10 08:03:27Z

2

You could do it basically with any language that supports regular expressions replacement.

Here's a 3 lines working C# example:

string text = "if((A==B)&&(C==D)&&((E==F)||(G==H))||(I)&&(J!=K))";
string pattern = @"\((?:(\w)((?:=|!)=)(\w))\)";
var replaced = Regex.Replace(text, pattern, m => string.Format("(string.Compare({0},{1}){2}0)", m.Groups[1].Value, m.Groups[3].Value, m.Groups[2].Value));

Console.WriteLine(replaced);

And the result:

if((string.Compare(A,B)==0)&&(string.Compare(C,D)==0)&&((string.Compare(E,F)==0)||(string.Compare(G,H)==0))||(I)&&(string.Compare(J,K)!=0))

answered May 10, 2011 at 8:03

Oscar Mederos

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2 Comments

Harish Over a year ago

I guess this is what I want.I will try to get the equivalent of it in Java as I am not well versed with c#

Oscar Mederos Over a year ago

@Harish Try doing it with Java. See how Java replaces regex matches, and then translate the code. The regular expression should be the same.

glenn jackman · Accepted Answer · 2011-05-10 13:28:55Z

2

sed -r 's/([[:alpha:]])([=!]=)([[:alpha:]])/string.Compare(\1,\3) \2 0/g'

The spaces around \2 aren't strictly necessary.

answered May 10, 2011 at 13:28

glenn jackman

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2 Comments

Oscar Mederos Over a year ago

Very interesting :) What does the 0/g at the end means?

glenn jackman Over a year ago

@Oscar, "0" is just a zero, for the string.Compare boolean value. "/" marks the end of the replacement text for sed's s command. "g" means perform the search and replace globally in the text.

Rajish · Accepted Answer · 2011-05-10 06:59:32Z

0

Basically you don't need to use awk or sed to construct the if statement. It is enough to write:

if [ A == B -a C == D -a ( E == F -o G == H ) -o I -a J != K ]; then
    your code here
fi

The == operator compares strings. If you wanted to compare numbers use -eq operator. See this chapter of bash manual (scroll down to test command), and the description of usage of primary conditional expressions

answered May 10, 2011 at 6:59

Rajish

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2 Comments

Oscar Mederos Over a year ago

I'm almost sure that he's not talking about it. What he wants is to convert some code file syntax to another.

Harish Over a year ago

actually you got my question wrong.Its about manipulating the text inside if loop not about if loop

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