undr

Personal C library with multiple utilities. The name undr provides from a short story by Jorge Luis Borges

Caveats

• This library has been developed on and for Linux following open source philosophy.
• Dependencies: openssl
• This library is available in AUR repositories (Arch Linux)

Utilities

• Format and prettify JSON, XML and HTML strings
• Arena allocator
• JWT decoder

Usage

Format JSON, XML or HTML

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <undr/format.h>

int main() {
  const char* json_input = "{\"a\":1,\"b\":[1,2]}";
  char* json = format_json(json_input, 2, 5);
  printf("formatted json:\n %s\n", json);

  const char* xml_input = "<?xml version=\"1.0\"?><root><user><name>John</name><id>1</id></user></root>";
  char* xml = format_xml(xml_input, 2, 5);
  printf("formatted xml:\n %s\n", xml);

  return 0;
}

Arena

#include <string.h>
#include <stdlib.h>
#include <undr/arena.h>

int main() {
  Arena *arena = arena_init(1024);

  int *numbers = arena_alloc(arena, 5 * sizeof(int));
  for (int i = 0; i < 5; i++) numbers[i] = i * 10;

  char *msg = arena_alloc(arena, 20);
  strcpy(msg, "Hello Arena!");

  arena_free(arena);

  return 0;
}

JWT decoder

#include <string.h>
#include <stdlib.h>
#include <undr/jwt.h>

int main() {
  Arena *arena = arena_init(1024);

  const char *raw_jwt =
        "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9."
        "eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MD"
        "IyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c";

  Jwt token = decode_jwt(arena, raw_jwt);

  if (token.header && token.payload) {
    printf("Header:\n %s\n", token.header);
    printf("Payload:\n %s\n", token.payload);
  }

  arena_free(arena);

  return 0;
}

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