initial: modular iptv-dl with runtime config from ~/.iptv-downloader/config.json

buf.c

@@ -0,0 +1,28 @@
+#include "buf.h"
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <stdio.h>
+
+void buf_init(Buf *b) {
+    b->data = malloc(4096); b->len = 0; b->cap = 4096; b->data[0] = 0;
+}
+
+void buf_free(Buf *b) {
+    free(b->data); b->data = NULL; b->len = 0; b->cap = 0;
+}
+
+void buf_append(Buf *b, const char *s, size_t n) {
+    while (b->len + n + 1 > b->cap) { b->cap *= 2; b->data = realloc(b->data, b->cap); }
+    memcpy(b->data + b->len, s, n);
+    b->len += n;
+    b->data[b->len] = 0;
+}
+
+void buf_str(Buf *b, const char *s) { buf_append(b, s, strlen(s)); }
+
+void buf_fmt(Buf *b, const char *fmt, ...) {
+    char tmp[4096]; va_list ap; va_start(ap, fmt);
+    vsnprintf(tmp, sizeof(tmp), fmt, ap); va_end(ap);
+    buf_str(b, tmp);
+}