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   1 #include "config.h"
   2 #include <stdio.h>
   3 #include <string.h>
   4
   5 /**
   6  * json_out - Code for creating simple JSON output.
   7  *
   8  * This code helps you create well-formed JSON strings.
   9  *
  10  * Author: Rusty Russell <rusty@rustcorp.com.au>
  11  * License: BSD-MIT
  12  *
  13  * Example:
  14  *      // Given "a 1 true" outputs {"argv1":"a","argv2":1,"argv3":true}
  15  *      // Print arguments as a JSON array.
  16  *      #include <ccan/json_out/json_out.h>
  17  *      #include <stdio.h>
  18  *      #include <string.h>
  19  *      #include <unistd.h>
  20  *
  21  *      // Simplistic test to see if str needs quotes.
  22  *      static bool can_be_json_literal(const char *str)
  23  *      {
  24  *              char *endp;
  25  *              if (strtol(str, &endp, 10) != LONG_MIN
  26  *                  && endp != str
  27  *                  && *endp == '\0')
  28  *                      return true;
  29  *              return !strcmp(str, "true")
  30  *                      || !strcmp(str, "false")
  31  *                      || !strcmp(str, "null");
  32  *      }
  33  *
  34  *      int main(int argc, char *argv[])
  35  *      {
  36  *              struct json_out *jout = json_out_new(NULL);
  37  *              size_t len;
  38  *              const char *p;
  39  *
  40  *              json_out_start(jout, NULL, '{');
  41  *              for (int i = 1; i < argc; i++) {
  42  *                      char fieldname[80];
  43  *                      sprintf(fieldname, "argv%i", i);
  44  *                      json_out_add(jout, fieldname,
  45  *                                   !can_be_json_literal(argv[i]),
  46  *                                   "%s", argv[i]);
  47  *              }
  48  *              json_out_end(jout, '}');
  49  *              // Force appending of \n
  50  *              json_out_direct(jout, 1)[0] = '\n';
  51  *              json_out_finished(jout);
  52  *
  53  *              // Now write it out.
  54  *              while ((p = json_out_contents(jout, &len)) != NULL) {
  55  *                      int i = write(STDOUT_FILENO, p, len);
  56  *                      if (i <= 0)
  57  *                              exit(1);
  58  *                      json_out_consume(jout, i);
  59  *              }
  60  *
  61  *              tal_free(jout);
  62  *              return 0;
  63  *      }
  64  *
  65  */
  66 int main(int argc, char *argv[])
  67 {
  68         /* Expect exactly one argument */
  69         if (argc != 2)
  70                 return 1;
  71
  72         if (strcmp(argv[1], "depends") == 0) {
  73                 printf("ccan/compiler\n");
  74                 printf("ccan/json_escape\n");
  75                 printf("ccan/membuf\n");
  76                 printf("ccan/tal\n");
  77                 printf("ccan/typesafe_cb\n");
  78                 return 0;
  79         }
  80
  81         return 1;
  82 }