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/*
* quick-start.c - Quick start example for libfyaml
*
* Demonstrates:
* - Parsing YAML from a file
* - Extracting values using path-based scanf
* - Modifying the document
* - Emitting as YAML
*
* Copyright (c) 2019-2025 Pantelis Antoniou <pantelis.antoniou@konsulko.com>
*
* SPDX-License-Identifier: MIT
*/
#include <stdlib.h>
#include <stdio.h>
#include <libfyaml.h>
int main(int argc, char *argv[])
{
struct fy_document *fyd = NULL;
unsigned int port;
char hostname[256];
int ret = EXIT_FAILURE;
const char *input_file = (argc > 1) ? argv[1] : "config.yaml";
// Parse YAML from string or file
fyd = fy_document_build_from_file(NULL, input_file);
if (!fyd) {
fprintf(stderr, "Failed to parse %s\n", input_file);
fprintf(stderr, "Note: You can create config.yaml or pass a file as argument\n");
goto cleanup;
}
// Extract values using path-based scanf
int count = fy_document_scanf(fyd,
"/server/port %u "
"/server/host %255s",
&port, hostname);
if (count != 2) {
fprintf(stderr, "Failed to extract server configuration\n");
fprintf(stderr, "Expected /server/port and /server/host in YAML\n");
goto cleanup;
}
printf("Current configuration: %s:%u\n", hostname, port);
// Modify document using path-based insertion
if (fy_document_insert_at(fyd, "/server", FY_NT,
fy_node_buildf(fyd, "timeout: 30"))) {
fprintf(stderr, "Failed to insert timeout setting\n");
goto cleanup;
}
printf("Added timeout setting\n");
// Emit as YAML
printf("\nUpdated configuration:\n");
if (fy_emit_document_to_fp(fyd, FYECF_SORT_KEYS, stdout)) {
fprintf(stderr, "Failed to emit document\n");
goto cleanup;
}
ret = EXIT_SUCCESS;
cleanup:
fy_document_destroy(fyd);
return ret;
}
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