find function name in a program file

Shell Programming and Scripting
1

Hello All,
Is there any way to find a function name in a program file using perl.

for example, there is a file called Test.C in that
.
.

void function1(..)
{
<some code>
}
int function2(..)
{
.
.
sam() /*RA abc100*/
...
..
..
xyz()/*RA abc201*/
..
.
}

from this I know only the string 'abc100', using this how can I find the function name and the other associate RA numbers within the funcion.

thanks in advance,
Parthiban.

2

Do you mean to search in a file for the given pattern?

grep 'abc100' TEST.C

Not sure I understood you correctly.

3

It will show only the particular line which contains abc100.
I want the function name which contains 'abc100' and other other numbers which having the same pattern 'RA '.

I tried the following

awk -F"RA " '{ print $2}' $FileName | awk '{print $1}'| sed 's/[-+;:!=?"|{}()<>~\%\$\@\#\^\&\*\[\\\/]/ /g' | sed '/^$/d' | uniq

it will list out all the strings with pattern "RA " in the file.

I just want to know the function name which contains the specific string, and the line numbers of starting of the function and ending of the function.

any idea?

4

try this

  • put this code in a file called script.pl or whatever you like:

$str=shift @ARGV;
while(<>){
$c++ if $sw && /\{/;
$c-- if $sw && /\}/;
if($sw && $c==0){
print "end line $.\n";
$sw=0;
}
if(!$sw && /(.+\(.*?\)).*\/.*RA $str/){
print "function $1\nstart line $.\n";
$sw=1;
}
}

  • your C program file assuming is named prog.c and has opening an closing curly braces, like this:

void function1(..)
{
<some code>
}
int function2(..)
{
.
.
sam() /RA abc100/
{
...
..
..
}
xyz()/RA abc201/
{
..
.
}

  • so if you do this you might get what you want:

perl script.pl abc100 prog.c

---------- Post updated at 08:12 PM ---------- Previous update was at 04:09 PM ----------

sorry I think i made a mistake, please use this perl script instead teh one i sent:

$str=shift @ARGV;
while(<>){
        if(/(.+\s+.+\(.*\))/){
                $func_name=$1;
                $func_start=$.;
                $sw=1;
                @ra=();
                next;
        }
        $c++ if $sw && /\{/;
        $c-- if $sw && /\}/; 
        if(/\/\*RA (.+)\*\//){
                push(@ra,$1);
        }
        if(/\/\*RA $str/){
                $print=1;
        }
        if($sw && $c==0){
                if($print){
                        print "here4\n";
                        print "function $func_name\n";
                        print "start line $func_start\n";
                        print "end line $.\n";
                        print "ra's:\n  ".join("\n  ",@ra)."\n";
                        $print=0;
                }
                $sw=0;
        }
}
1 Like
5

Hi, Thanks for your great work. but This script doesn't print anything. I used the the following file for testing

file name : prog.c

function1()
{
  abcd;
  xyz;
  sam()/*RA abc00123*/
}

function2()
{
  abcd;
  xyz;
  sam;/*RA xyz00891*/
  sdfsdg;
  dgsdg;
  ertwt; /*RA abc100*/
  sf;
}

>perl script.pl abc100 prog.c
>
6

try this version

$str=shift @ARGV;
while(<>){
        if(!$sw && /(.+\(.*\))/){
                $func_name=$1;
                $func_start=$.;
                $sw=1;
                @ra=();
                next;
        }
        $c++ if $sw && /\{/;
        $c-- if $sw && /\}/; 
        if(/\/\*RA (.+)\*\//){
                push(@ra,$1);
        }
        if(/\/\*RA $str/){
                $print=1;
        }
        if($sw && $c==0){
                if($print){
                        print "here4\n";
                        print "function $func_name\n";
                        print "start line $func_start\n";
                        print "end line $.\n";
                        print "ra's:\n  ".join("\n  ",@ra)."\n";
                        $print=0;
                }
                $sw=0;
        }
}
1 Like
7

Hi, Its working great... Thank you very much.. you made my work simple now.. As am new to perl can you explain me how it works.?

8

here's the code with some comments to try to explain...i hope it helps..

$str=shift @ARGV;
while(<>){
        # match function name and save name and line to display later in
        # case the RA is found
        if(!$sw && /(.+\(.*\))/){
                $func_name=$1;
                $func_start=$.;
                $sw=1;  
                @ra=();
                next;
        }       
        # those counters basically server to know if we are ($c>0) or not ($c==0) 
        # inside a function body i.e. between { and } 
        $c++ if $sw && /\{/;
        $c-- if $sw && /\}/; 

        # match RA string and save it in a list
        if(/\/\*RA (.+)\*\//){
                push(@ra,$1);
        }       
                
        # flag to know if the RA in questions was found, so we'll preint everything
       # we've saved   
        if(/\/\*RA $str/){ 
                $print=1;
        }       
                
        # if we are at the end of a function $sw==1 and $c==0 then 
        if($sw && $c==0){ 
            # we test if any of the RAs in the function was the one we were 
            # looking for, if so print all the elements
                if($print){
                        print "function $func_name\n";
                        print "start line $func_start\n";
                        print "end line $.\n";
                        print "ra's:\n  ".join("\n  ",@ra)."\n";
                        $print=0;
                }
                $sw=0;
        }       
}
1 Like
9

what is
if(!$sw && /(.+\(.*\))/) looking for. and we didn't declare $sw previously, how it works and what is the use for it.?

Thanks & Regards,
Parthiban.