Question

I have a file with function signatures like this:

void something(float a, int b, char c);

Using shell scripts or similar how would you process this, so as to end up with:

float int char

Answer 1

Would this work? I had to do a bit of gymnastics with the IFS variable and some for loops, but it seems to work fine for me. If some of the “void” lines have leading spaces or tabs, you’ll have to adjust the sed expression however…

test.txt

void something(float a, int b, char c);
void something_else(string s, int p);
void test(float test);
void tata(string k);
void foobar(float a, int l, char e);

test.sh

#!/bin/bash
filename=$1
OLD_IFS=$IFS
IFS=$'\n'
trap "rm -f $$.tmp" EXIT SIGHUP
for line in $(egrep -i "^void\ " $filename | sed -e 's/^void \w*(\(.*\));/\1/'); do
        IFS=,
        for s in $line; do
                echo $s | awk '{print $1}' >> $$.tmp
        done
        IFS=$'\n'
done
IFS=$OLD_IFS
sort $$.tmp | uniq | tr "\n" " "
echo
exit 0

Result:

$ ./test.sh test.txt
char float int string