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-rw-r--r--libjsmn/example/jsondump.c112
-rw-r--r--libjsmn/example/simple.c75
2 files changed, 187 insertions, 0 deletions
diff --git a/libjsmn/example/jsondump.c b/libjsmn/example/jsondump.c
new file mode 100644
index 0000000000000..3490bbf499007
--- /dev/null
+++ b/libjsmn/example/jsondump.c
@@ -0,0 +1,112 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include "../jsmn.h"
+
+/*
+ * An example of reading JSON from stdin and printing its content to stdout.
+ * The output looks like YAML, but I'm not sure if it's really compatible.
+ */
+
+static int dump(const char *js, jsmntok_t *t, size_t count, int indent) {
+ int i, j, k;
+ if (count == 0) {
+ return 0;
+ }
+ if (t->type == JSMN_PRIMITIVE) {
+ printf("%.*s", t->end - t->start, js+t->start);
+ return 1;
+ } else if (t->type == JSMN_STRING) {
+ printf("'%.*s'", t->end - t->start, js+t->start);
+ return 1;
+ } else if (t->type == JSMN_OBJECT) {
+ printf("\n");
+ j = 0;
+ for (i = 0; i < t->size; i++) {
+ for (k = 0; k < indent; k++) printf(" ");
+ j += dump(js, t+1+j, count-j, indent+1);
+ printf(": ");
+ j += dump(js, t+1+j, count-j, indent+1);
+ printf("\n");
+ }
+ return j+1;
+ } else if (t->type == JSMN_ARRAY) {
+ j = 0;
+ printf("\n");
+ for (i = 0; i < t->size; i++) {
+ for (k = 0; k < indent-1; k++) printf(" ");
+ printf(" - ");
+ j += dump(js, t+1+j, count-j, indent+1);
+ printf("\n");
+ }
+ return j+1;
+ }
+ return 0;
+}
+
+int main() {
+ int r;
+ int eof_expected = 0;
+ char *js = NULL;
+ size_t jslen = 0;
+ char buf[BUFSIZ];
+
+ jsmn_parser p;
+ jsmntok_t *tok;
+ size_t tokcount = 2;
+
+ /* Prepare parser */
+ jsmn_init(&p);
+
+ /* Allocate some tokens as a start */
+ tok = malloc(sizeof(*tok) * tokcount);
+ if (tok == NULL) {
+ fprintf(stderr, "malloc(): errno=%d\n", errno);
+ return 3;
+ }
+
+ for (;;) {
+ /* Read another chunk */
+ r = fread(buf, 1, sizeof(buf), stdin);
+ if (r < 0) {
+ fprintf(stderr, "fread(): %d, errno=%d\n", r, errno);
+ return 1;
+ }
+ if (r == 0) {
+ if (eof_expected != 0) {
+ return 0;
+ } else {
+ fprintf(stderr, "fread(): unexpected EOF\n");
+ return 2;
+ }
+ }
+
+ js = realloc(js, jslen + r + 1);
+ if (js == NULL) {
+ fprintf(stderr, "realloc(): errno=%d\n", errno);
+ return 3;
+ }
+ strncpy(js + jslen, buf, r);
+ jslen = jslen + r;
+
+again:
+ r = jsmn_parse(&p, js, jslen, tok, tokcount);
+ if (r < 0) {
+ if (r == JSMN_ERROR_NOMEM) {
+ tokcount = tokcount * 2;
+ tok = realloc(tok, sizeof(*tok) * tokcount);
+ if (tok == NULL) {
+ fprintf(stderr, "realloc(): errno=%d\n", errno);
+ return 3;
+ }
+ goto again;
+ }
+ } else {
+ dump(js, tok, p.toknext, 0);
+ eof_expected = 1;
+ }
+ }
+
+ return 0;
+}
diff --git a/libjsmn/example/simple.c b/libjsmn/example/simple.c
new file mode 100644
index 0000000000000..a6f8e6a98f7ef
--- /dev/null
+++ b/libjsmn/example/simple.c
@@ -0,0 +1,75 @@
+#include <stdio.h>
+#include <string.h>
+#include "../jsmn.h"
+
+/*
+ * A small example of jsmn parsing when JSON structure is known and number of
+ * tokens is predictable.
+ */
+
+const char *JSON_STRING =
+ "{\"user\": \"johndoe\", \"admin\": false, \"uid\": 1000,\n "
+ "\"groups\": [\"users\", \"wheel\", \"audio\", \"video\"]}";
+
+static int jsoneq(const char *json, jsmntok_t *tok, const char *s) {
+ if (tok->type == JSMN_STRING && (int) strlen(s) == tok->end - tok->start &&
+ strncmp(json + tok->start, s, tok->end - tok->start) == 0) {
+ return 0;
+ }
+ return -1;
+}
+
+int main() {
+ int i;
+ int r;
+ jsmn_parser p;
+ jsmntok_t t[128]; /* We expect no more than 128 tokens */
+
+ jsmn_init(&p);
+ r = jsmn_parse(&p, JSON_STRING, strlen(JSON_STRING), t, sizeof(t)/sizeof(t[0]));
+ if (r < 0) {
+ printf("Failed to parse JSON: %d\n", r);
+ return 1;
+ }
+
+ /* Assume the top-level element is an object */
+ if (r < 1 || t[0].type != JSMN_OBJECT) {
+ printf("Object expected\n");
+ return 1;
+ }
+
+ /* Loop over all keys of the root object */
+ for (i = 1; i < r; i++) {
+ if (jsoneq(JSON_STRING, &t[i], "user") == 0) {
+ /* We may use strndup() to fetch string value */
+ printf("- User: %.*s\n", t[i+1].end-t[i+1].start,
+ JSON_STRING + t[i+1].start);
+ i++;
+ } else if (jsoneq(JSON_STRING, &t[i], "admin") == 0) {
+ /* We may additionally check if the value is either "true" or "false" */
+ printf("- Admin: %.*s\n", t[i+1].end-t[i+1].start,
+ JSON_STRING + t[i+1].start);
+ i++;
+ } else if (jsoneq(JSON_STRING, &t[i], "uid") == 0) {
+ /* We may want to do strtol() here to get numeric value */
+ printf("- UID: %.*s\n", t[i+1].end-t[i+1].start,
+ JSON_STRING + t[i+1].start);
+ i++;
+ } else if (jsoneq(JSON_STRING, &t[i], "groups") == 0) {
+ int j;
+ printf("- Groups:\n");
+ if (t[i+1].type != JSMN_ARRAY) {
+ continue; /* We expect groups to be an array of strings */
+ }
+ for (j = 0; j < t[i+1].size; j++) {
+ jsmntok_t *g = &t[i+j+2];
+ printf(" * %.*s\n", g->end - g->start, JSON_STRING + g->start);
+ }
+ i += t[i+1].size + 1;
+ } else {
+ printf("Unexpected key: %.*s\n", t[i].end-t[i].start,
+ JSON_STRING + t[i].start);
+ }
+ }
+ return 0;
+}