Compress JSON file by eliminating whitespace

Looks like you're looking for a JSON minifier.

There are some around, both online and standalone.

Try googling these terms + your favorite language, I'm sure you'll find something that suits your needs.

There are other tools that modify your JSON to make it smaller, but you'll end up with a different JSON, I guess. Haven't tried those.

Using GNU awk for RT:

$ awk 'BEGIN{RS="\""} NR%2{gsub(/[[:space:]]/,"")} {ORS=RT;print} END{printf "\n"}' file"name_id":"Richard Feynman","occupation":"Professional Bongos Player"

The following flex(1) program will do the work. It makes a lexical analisys of json source and eliminates comments and spaces between tokens, respecting the in-string spaces. It also recognizes unquoted identifiers, and quotes them.

To compile it, just do

make json

Use it with the following command:

json [ file ... ]

if you don't specify a file, the program will read from stdin.

Here's the source:

%{/* json-min.  JSON minimizer. * Author: Luis Colorado <lc@luiscoloradosistemas.com> * Date: Wed Aug 13 07:35:23 EEST 2014 * Disclaimer: This program is GPL, as of GPL version 3, you * may have received a copy of that document, or you can * instead look at http://www.gnu.org/licenses/gpl.txt to read * it.  There's no warranty, nor assumed nor implicit on the * use of this program, you receive it `as is' so whatever you * do with it is only your responsibility.  Luis Colorado * won't assume any responsibility of the use or misuse of * this program.  You are warned. */%}dec ([1-9][0-9]*)oct (0[0-7]*)hex (0[xX][0-9a-fA-F]*)doub    ({dec}"."([0-9]*)?|{dec}?"."[0-9]+)strd    (\"([^\"]|\\.)*\")t   "true"f   "false"n   "null"com1    "//".*com2b   "/*"endc    "*/"ident   ([a-zA-Z_][a-zA-Z0-9_]*)%x INCOMMENT%option noyywrap%%{dec}           |{oct}           |{hex}           |{doub}          |{strd}              |{t}             |{f}         |{n}         |"{"         |":"         |";"         |"}"         |"["         |"]"         |","         ECHO;[\ \t\n]        |{com1}          ;{com2b}         BEGIN(INCOMMENT);<INCOMMENT>.        ;<INCOMMENT>{endc}   BEGIN(INITIAL);{ident}         { fprintf(stderr, "WARNING:"                "unquoted identifier %s "                "in source.  Quoting.\n",                yytext);              printf("\"%s\"", yytext);            }.           { fprintf(stderr,                "WARNING: unknown symbol %s "                "in source, copied to output\n",                yytext);              ECHO;            }%%void process(const char *fn);int main(int argc, const char **argv){    int i;    if (argc > 1) for (i = 1; i < argc; i++)        process(argv[i]);    else process(NULL); /* <-- stdin */} /* main */void process(const char *fn){    FILE *f = stdin;    if (fn) {        f = fopen(fn, "r");        if (!f) {            fprintf(stderr,                "ERROR:fopen:%s:%s(errno=%d)\n",                fn, strerror(errno), errno);            exit(EXIT_FAILURE);        } /* if */    } /* if */    yyin = f;    yylex();    if (fn) /* only close if we opened, don't close stdin. */        fclose(f);    printf("\n");}

I have just written it, so there's little testing on it. Use it with care (conserve a backup of your original file) It doesn't overwrite the original file, just outputs to stdout, so you don't overwrite your data using it.

BR,Luis