First commit XiUOS

tool/shell/letter-shell/file_ext/utility.c

@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2020 AIIT XUOS Lab
+ * XiUOS is licensed under Mulan PSL v2.
+ * You can use this software according to the terms and conditions of the Mulan PSL v2.
+ * You may obtain a copy of Mulan PSL v2 at:
+ *        http://license.coscl.org.cn/MulanPSL2
+ * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+ * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+ * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+ * See the Mulan PSL v2 for more details.
+*/
+
+#include <xiuos.h>
+
+#ifdef FS_VFS
+
+#include <string.h>
+#include <stdlib.h>
+#include <iot-vfs_posix.h>
+#include "utility.h"
+
+int IsPrefixedWith(char *str, char *prefix)
+{
+    while (*prefix != '\0') {
+        if (*str != *prefix)
+            return 0;
+        str++;
+        prefix++;
+    }
+    return 1;
+}
+
+char *RemoveUnsafePrefix(char *file_name)
+{
+    char *ret = file_name;
+
+    while (1) {
+        if (*ret == '/') {
+            ret++;
+            continue;
+        }
+        if (IsPrefixedWith(ret, "/../" + 1)) {
+            ret += 3;
+            continue;
+        }
+        char *p = strstr(ret, "/../");
+        if (!p)
+            break;
+        ret = p + 4;
+    }
+
+    return ret;
+}
+
+int IsSuffixedWith(char *file_name, char *suffix)
+{
+    int len = strlen(file_name);
+    int suff_len = strlen(suffix);
+
+    return len > suff_len &&
+            strcmp(&file_name[len - suff_len], suffix) == 0;
+}
+
+int TruncateExtension(char *file_name, char *ext)
+{
+    int len = strlen(file_name);
+    int ext_len = strlen(ext);
+
+    if (!IsSuffixedWith(file_name, ext))
+        return -1;
+
+    file_name[len - ext_len] = '\0';
+    return 0;
+}
+
+unsigned char read8(int fd)
+{
+    unsigned char ret;
+
+    read(fd, &ret, 1);
+
+    return ret;
+}
+
+uint16_t read16Le(int fd)
+{
+    uint16_t ret = 0;
+    unsigned char buf[2];
+
+    read(fd, buf, 2);
+    for (int i = 0; i < 2; i++)
+        ret |= (uint16_t)buf[i] << (i * 8);
+
+    return ret;
+}
+
+uint32_t read32Le(int fd)
+{
+    uint32_t ret = 0;
+    unsigned char buf[4];
+
+    read(fd, buf, 4);
+    for (int i = 0; i < 4; i++)
+        ret |= (uint32_t)buf[i] << (i * 8);
+
+    return ret;
+}
+
+uint64_t read64Le(int fd)
+{
+    uint64_t ret = 0;
+    unsigned char buf[8];
+
+    read(fd, buf, 8);
+    for (int i = 0; i < 8; i++)
+        ret |= (uint32_t)buf[i] << (i * 8);
+
+    return ret;
+}
+
+#endif