apple2ix/externals/jsmn/example/jsondump.c

127 lines
2.8 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include "../jsmn.h"
/* Function realloc_it() is a wrapper function for standart realloc()
* with one difference - it frees old memory pointer in case of realloc
* failure. Thus, DO NOT use old data pointer in anyway after call to
* realloc_it(). If your code has some kind of fallback algorithm if
* memory can't be re-allocated - use standart realloc() instead.
*/
static inline void *realloc_it(void *ptrmem, size_t size) {
void *p = realloc(ptrmem, size);
if (!p) {
free (ptrmem);
fprintf(stderr, "realloc(): errno=%d\n", errno);
}
return p;
}
/*
* 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_it(js, jslen + r + 1);
if (js == NULL) {
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_it(tok, sizeof(*tok) * tokcount);
if (tok == NULL) {
return 3;
}
goto again;
}
} else {
dump(js, tok, p.toknext, 0);
eof_expected = 1;
}
}
return 0;
}