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AKAMAN source: json.h

AKAMAN json.h — JSON parsing and protocol data handling.

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AKAMAN

A small Linux C utility that retrieves the compact documentation fragment an AI agent needs from the host where it is running.

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json.c

JSON parsing and protocol data handling. This is the released v0.1.0 source, shown in full so you can read it before downloading the archive.

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#include "json.h"#include <stdlib.h>#include <string.h>#include <ctype.h>#include <stdio.h>static int jv_grow_items(jv *v) {	if (v->ni == v->cap) {		int nc = v->cap ? v->cap * 2 : 8;		jv **p = realloc(v->items, (size_t)nc * sizeof(jv *));		if (!p) return 0;		v->cap = nc;		v->items = p;	}	return 1;}static int jv_grow_kv(jv *v) {	if (v->nk == v->kcap) {		int nc = v->kcap ? v->kcap * 2 : 8;		void *p = realloc(v->kv, (size_t)nc * sizeof(*v->kv));		if (!p) return 0;		v->kcap = nc;		v->kv = p;	}	return 1;}static jv *jv_new(int t) {	jv *v = calloc(1, sizeof *v);	v->t = t;	return v;}static void skipws(const char *s, size_t len, size_t *pos) {	while (*pos < len && (s[*pos] == ' ' || s[*pos] == '\t' || s[*pos] == '\n' || s[*pos] == '\r'))		(*pos)++;}static int hexval(char c) {	if (c >= '0' && c <= '9') return c - '0';	if (c >= 'a' && c <= 'f') return c - 'a' + 10;	if (c >= 'A' && c <= 'F') return c - 'A' + 10;	return -1;}static size_t utf8_sequence(const unsigned char *p, size_t n) {	if (n == 0 || p[0] < 0x80) return n ? 1 : 0;	if (p[0] >= 0xC2 && p[0] <= 0xDF)		return n >= 2 && (p[1] & 0xC0) == 0x80 ? 2 : 0;	if (p[0] == 0xE0)		return n >= 3 && p[1] >= 0xA0 && p[1] <= 0xBF && (p[2] & 0xC0) == 0x80 ? 3 : 0;	if (p[0] >= 0xE1 && p[0] <= 0xEC)		return n >= 3 && (p[1] & 0xC0) == 0x80 && (p[2] & 0xC0) == 0x80 ? 3 : 0;	if (p[0] == 0xED)		return n >= 3 && p[1] >= 0x80 && p[1] <= 0x9F && (p[2] & 0xC0) == 0x80 ? 3 : 0;	if (p[0] >= 0xEE && p[0] <= 0xEF)		return n >= 3 && (p[1] & 0xC0) == 0x80 && (p[2] & 0xC0) == 0x80 ? 3 : 0;	if (p[0] == 0xF0)		return n >= 4 && p[1] >= 0x90 && p[1] <= 0xBF &&		       (p[2] & 0xC0) == 0x80 && (p[3] & 0xC0) == 0x80 ? 4 : 0;	if (p[0] >= 0xF1 && p[0] <= 0xF3)		return n >= 4 && (p[1] & 0xC0) == 0x80 &&		       (p[2] & 0xC0) == 0x80 && (p[3] & 0xC0) == 0x80 ? 4 : 0;	if (p[0] == 0xF4)		return n >= 4 && p[1] >= 0x80 && p[1] <= 0x8F &&		       (p[2] & 0xC0) == 0x80 && (p[3] & 0xC0) == 0x80 ? 4 : 0;	return 0;}static int utf8_valid(const char *s, size_t len) {	for (size_t i = 0; i < len;) {		size_t n = utf8_sequence((const unsigned char *)s + i, len - i);		if (!n) return 0;		i += n;	}	return 1;}static jv *parse_value(const char *s, size_t len, size_t *pos, int *err);static jv *parse_string(const char *s, size_t len, size_t *pos, int *err) {	(*pos)++;	gbuf b;	gbuf_init(&b);	while (*pos < len) {		char c = s[*pos];		if (c == '"') {			(*pos)++;			if (b.failed) { gbuf_free(&b); *err = 1; return NULL; }			jv *v = jv_new(3);			if (!v) { gbuf_free(&b); *err = 1; return NULL; }			v->str = b.p ? b.p : strdup("");			if (!v->str) { free(v); *err = 1; return NULL; }			return v;		}		if (c == '\\') {			(*pos)++;			if (*pos >= len) { *err = 1; break; }			char e = s[*pos];			(*pos)++;			switch (e) {			case '"':  gbuf_addch(&b, '"'); break;			case '\\': gbuf_addch(&b, '\\'); break;			case '/':  gbuf_addch(&b, '/'); break;			case 'b':  gbuf_addch(&b, '\b'); break;			case 'f':  gbuf_addch(&b, '\f'); break;			case 'n':  gbuf_addch(&b, '\n'); break;			case 'r':  gbuf_addch(&b, '\r'); break;			case 't':  gbuf_addch(&b, '\t'); break;			case 'u': {				if (len - *pos < 4) { *err = 1; break; }				int cp = 0, ok = 1;				for (int i = 0; i < 4; i++) {					int h = hexval(s[*pos + (size_t)i]);					if (h < 0) { ok = 0; break; }					cp = cp * 16 + h;				}				if (!ok) { *err = 1; break; }				*pos += 4;				if (cp >= 0xD800 && cp <= 0xDBFF) {					if (len - *pos < 6 || s[*pos] != '\\' || s[*pos + 1] != 'u') { *err = 1; break; }					int low = 0;					for (int i = 0; i < 4; i++) {						int h = hexval(s[*pos + 2 + (size_t)i]);						if (h < 0) { *err = 1; break; }						low = low * 16 + h;					}					if (*err || low < 0xDC00 || low > 0xDFFF) { *err = 1; break; }					*pos += 6;					cp = 0x10000 + ((cp - 0xD800) << 10) + (low - 0xDC00);				} else if (cp >= 0xDC00 && cp <= 0xDFFF) {					*err = 1;					break;				}				if (cp < 0x80) gbuf_addch(&b, (char)cp);				else if (cp < 0x800) {					gbuf_addch(&b, (char)(0xC0 | (cp >> 6)));					gbuf_addch(&b, (char)(0x80 | (cp & 0x3F)));				} else if (cp < 0x10000) {					gbuf_addch(&b, (char)(0xE0 | (cp >> 12)));					gbuf_addch(&b, (char)(0x80 | ((cp >> 6) & 0x3F)));					gbuf_addch(&b, (char)(0x80 | (cp & 0x3F)));				} else {					gbuf_addch(&b, (char)(0xF0 | (cp >> 18)));					gbuf_addch(&b, (char)(0x80 | ((cp >> 12) & 0x3F)));					gbuf_addch(&b, (char)(0x80 | ((cp >> 6) & 0x3F)));					gbuf_addch(&b, (char)(0x80 | (cp & 0x3F)));				}				break;			}			default: *err = 1;			}			if (*err) break;		} else if ((unsigned char)c < 0x20) {			*err = 1;			break;		} else {			gbuf_addch(&b, c);			(*pos)++;		}	}	gbuf_free(&b);	return NULL;}static jv *parse_value(const char *s, size_t len, size_t *pos, int *err) {	skipws(s, len, pos);	if (*pos >= len) { *err = 1; return NULL; }	size_t start = *pos;	char c = s[*pos];	if (c == '"') {		jv *v = parse_string(s, len, pos, err);		if (v) { v->raw = s + start; v->rawlen = *pos - start; }		return v;	}	if (c == '{') {		(*pos)++;		jv *v = jv_new(5);		if (!v) { *err = 1; return NULL; }		skipws(s, len, pos);		if (*pos < len && s[*pos] == '}') {			(*pos)++;			v->raw = s + start; v->rawlen = *pos - start;			return v;		}		for (;;) {			skipws(s, len, pos);			jv *k = parse_string(s, len, pos, err);			if (!k) { jv_free(v); return NULL; }			skipws(s, len, pos);			if (*pos >= len || s[*pos] != ':') { *err = 1; jv_free(v); free(k); return NULL; }			(*pos)++;			jv *val = parse_value(s, len, pos, err);			if (!val) { *err = 1; jv_free(v); free(k); return NULL; }			if (!jv_grow_kv(v)) { *err = 1; jv_free(v); free(k->str); free(k); jv_free(val); return NULL; }			v->kv[v->nk].k = k->str;			v->kv[v->nk].v = val;			v->nk++;			free(k);			skipws(s, len, pos);			if (*pos >= len) { *err = 1; jv_free(v); return NULL; }			if (s[*pos] == ',') { (*pos)++; continue; }			if (s[*pos] == '}') {				(*pos)++;				v->raw = s + start; v->rawlen = *pos - start;				return v;			}			*err = 1;			jv_free(v);			return NULL;		}	}	if (c == '[') {		(*pos)++;		jv *v = jv_new(4);		if (!v) { *err = 1; return NULL; }		skipws(s, len, pos);		if (*pos < len && s[*pos] == ']') {			(*pos)++;			v->raw = s + start; v->rawlen = *pos - start;			return v;		}		for (;;) {			jv *val = parse_value(s, len, pos, err);			if (!val) { jv_free(v); return NULL; }			if (!jv_grow_items(v)) { *err = 1; jv_free(v); return NULL; }			v->items[v->ni++] = val;			skipws(s, len, pos);			if (*pos >= len) { *err = 1; jv_free(v); return NULL; }			if (s[*pos] == ',') { (*pos)++; continue; }			if (s[*pos] == ']') {				(*pos)++;				v->raw = s + start; v->rawlen = *pos - start;				return v;			}			*err = 1;			jv_free(v);			return NULL;		}	}	if (c == 't') {		if (len - *pos >= 4 && memcmp(s + *pos, "true", 4) == 0) {			*pos += 4;			jv *v = jv_new(1); if (!v) { *err = 1; return NULL; } v->b = 1;			v->raw = s + start; v->rawlen = 4;			return v;		}		*err = 1; return NULL;	}	if (c == 'f') {		if (len - *pos >= 5 && memcmp(s + *pos, "false", 5) == 0) {			*pos += 5;			jv *v = jv_new(1); if (!v) { *err = 1; return NULL; } v->b = 0;			v->raw = s + start; v->rawlen = 5;			return v;		}		*err = 1; return NULL;	}	if (c == 'n') {		if (len - *pos >= 4 && memcmp(s + *pos, "null", 4) == 0) {			*pos += 4;			jv *v = jv_new(0); if (!v) { *err = 1; return NULL; }			v->raw = s + start; v->rawlen = 4;			return v;		}		*err = 1; return NULL;	}	/* number */	{		size_t p = *pos;		if (s[p] == '-') p++;		int digits = 0;		if (p < len && s[p] == '0') {			p++;			digits = 1;			if (p < len && isdigit((unsigned char)s[p])) { *err = 1; return NULL; }		} else {			while (p < len && isdigit((unsigned char)s[p])) { p++; digits++; }		}		if (p < len && s[p] == '.') {			p++;			size_t frac = p;			while (p < len && isdigit((unsigned char)s[p])) p++;			if (p == frac) { *err = 1; return NULL; }		}		if (p < len && (s[p] == 'e' || s[p] == 'E')) {			p++;			if (p < len && (s[p] == '+' || s[p] == '-')) p++;			size_t exp = p;			while (p < len && isdigit((unsigned char)s[p])) p++;			if (p == exp) { *err = 1; return NULL; }		}		if (digits == 0) { *err = 1; return NULL; }		jv *v = jv_new(2);		if (!v) { *err = 1; return NULL; }		char tmp[64];		size_t tl = p - *pos;		size_t tmp_len = tl < sizeof tmp ? tl : sizeof tmp - 1;		memcpy(tmp, s + *pos, tmp_len);		tmp[tmp_len] = 0;		v->num = strtod(tmp, NULL);		v->raw = s + *pos;		v->rawlen = p - *pos;		*pos = p;		return v;	}}jv *json_parse(const char *s, size_t len) {	if (!s || !utf8_valid(s, len)) return NULL;	size_t pos = 0;	int err = 0;	jv *v = parse_value(s, len, &pos, &err);	if (err || !v) {		if (v) jv_free(v);		return NULL;	}	skipws(s, len, &pos);	if (pos < len) {		jv_free(v);		return NULL;	}	return v;}jv *jv_get(jv *obj, const char *key) {	if (!obj || obj->t != 5) return NULL;	for (int i = 0; i < obj->nk; i++)		if (strcmp(obj->kv[i].k, key) == 0) return obj->kv[i].v;	return NULL;}const char *jv_str(jv *v) { return (v && v->t == 3) ? v->str : NULL; }void jv_free(jv *v) {	if (!v) return;	if (v->t == 3) free(v->str);	if (v->t == 4) {		for (int i = 0; i < v->ni; i++) jv_free(v->items[i]);		free(v->items);	}	if (v->t == 5) {		for (int i = 0; i < v->nk; i++) {			free(v->kv[i].k);			jv_free(v->kv[i].v);		}		free(v->kv);	}	free(v);}void json_escape(gbuf *b, const char *s, size_t len) {	gbuf_addch(b, '"');	for (size_t i = 0; i < len; i++) {		unsigned char c = (unsigned char)s[i];		switch (c) {		case '"':  gbuf_adds(b, "\\\""); break;		case '\\': gbuf_adds(b, "\\\\"); break;		case '\n': gbuf_adds(b, "\\n"); break;		case '\r': gbuf_adds(b, "\\r"); break;		case '\t': gbuf_adds(b, "\\t"); break;		case '\b': gbuf_adds(b, "\\b"); break;		case '\f': gbuf_adds(b, "\\f"); break;		default:			if (c < 0x20) {				char t[8];				snprintf(t, sizeof t, "\\u%04x", c);				gbuf_adds(b, t);			} else if (c >= 0x80) {				size_t n = utf8_sequence((const unsigned char *)s + i, len - i);				if (n) {					gbuf_addn(b, s + i, n);					i += n - 1;				} else {					char t[8];					snprintf(t, sizeof t, "\\u%04x", c);					gbuf_adds(b, t);				}			} else {				gbuf_addch(b, (char)c);			}		}	}	gbuf_addch(b, '"');}

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