Shell Programming and Scripting

awk -F'$' -v OFS="$" '{$2="latex " $2; $4="latex " $4} 1' file1  
Solve the equation $latex x^2=5$. Prove that $latex x$ is an irrational number.

awk -F'$' -v OFS='$' '{ for( I = 2; I <= NF; I+=2 )
  $I = "latex " $I
} 1' file1

Solve the equation $latex x^2=5$. Prove that $latex x$ is an irrational number.

my $str='$1 first $a second $2 third $b forth $3';
print $str,"\n";
$str=~s/\$
(?=
(?:[^\$]*\$[^\$]*\$)*[^\$]*$)
/-/gx;
print $str,"\n";