awk regex example

Question

Input format :

"130234":"f",
"130235":"m",
"130236":"f",
"130237":"f",

I want convert the above input from file to below output using awk command. 1. truncate the last "," and enclose with curly brace. Can any one help me on this.

{"130234":"f",
"130235":"m",
"130236":"f",
"130237":"f"}

Answer 1

You should use sed for such trivial substitution:

$ sed '1s/^/{/;$s/,$/}/' file
{"130234":"f",
"130235":"m",
"130236":"f",
"130237":"f"}

Answer 2

Through awk,

$ awk 'BEGIN{printf "{"}{if (a) print a; a=$0}END{sub(/,$/, "}");print}' file
{"130234":"f",
"130235":"m",
"130236":"f",
"130237":"f"}