Implemented fclose() and strrchr()

photon/libc/include/string.h

@@ -19,6 +19,8 @@ extern int strncmp(const char *a, const char *b, size_t sz);
 extern char *strcpy(char *dest, const char *src);
 extern char *strncpy(char *dest, const char *src, size_t sz);
 
+extern char *strrchr(const char *s, int c);
+
 extern char *strdup(const char *s);
 
 #if defined(__cplusplus)

photon/libc/stdio/fclose.c

@@ -0,0 +1,15 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <__fio.h>
+
+int fclose(FILE *fp)
+{
+    int res = __fio_fclose(fp);
+    if (res != 0) {
+        return EOF;
+    }
+
+    free(fp);
+    return 0;
+}

photon/libc/string/strrchr.c

@@ -0,0 +1,15 @@
+#include <string.h>
+
+char *strrchr(const char *s, int c)
+{
+    /* include null term */
+    long sz = strlen(s) + 1;
+
+    for (long i = sz; i >= 0; i--) {
+        if (s[i] == c) {
+            return (char *)(s + i);
+        }
+    }
+
+    return NULL;
+}

photon/libc/sys/magenta/fio.c

@@ -61,6 +61,15 @@ int __fio_fopen(const char *path, const char *mode, struct __io_file *fp)
     return 0;
 }
 
+int __fio_fclose(struct __io_file *fp)
+{
+    if (mx_handle_close(fp->handle) != MX_OK) {
+        return -1;
+    }
+
+    return 0;
+}
+
 int __fio_fdopen(mx_handle_t fd, const char *mode, struct __io_file *fp)
 {
     /* TODO validate handle and mode */