add threaded filewatcher

src/string/string.h

@@ -0,0 +1,31 @@
+#ifndef HI_STRING_H_
+#define HI_STRING_H_
+
+#include <stddef.h>
+
+/**
+ * @brief Copy file content to a null terminated string, allocating memory while
+ * reading.
+ *
+ * This doesn't assume it can read file size, so it allocates memory in chunks
+ * (default 4096 bytes) and keeps reading until 0 bytes is read. If nmax is
+ * non-zero, instead that amount of bytes is allocated and that is read.
+ *
+ * In either case, the string is reallocated to match the length before
+ * returning.
+ * @param filename
+ * @param nread if not null, this will have the total amount bytes read
+ * @param nmax if not 0, this amount of memory in bytes is read and used as
+ * initial allocation
+ */
+const char *hi_string_from_file_dyn(const char *filename, size_t *nread,
+                                    size_t nmax);
+
+/**
+ * Find if filename exists at the end of path.
+ *
+ * @return 0 if not found, positive if found
+ */
+int hi_path_has_filename(const char *path, const char *filename);
+
+#endif // HI_STRING_H_