Implemented lots of new functions

photon/libc/string/fread.c

@@ -0,0 +1,12 @@
+#include <stdio.h>
+#include <__fio.h>
+
+size_t fread(void *ptr, size_t size, size_t count, FILE *fp)
+{
+    if (!size || !count) {
+        return 0;
+    }
+
+    unsigned int written = __fio_read(fp, ptr, size * count);
+    return written / size;
+}

photon/libc/string/strcmp.c

@@ -0,0 +1,19 @@
+int strcmp(const char *s1, const char *s2)
+{
+    int i;
+    for (i = 0; s1[i] == s2[i]; i++)
+        if (s1[i] == '\0')
+            return 0;
+
+    return s1[i] - s2[i];
+}
+
+int strncmp(const char *s1, const char *s2, unsigned int n)
+{
+    for (; n > 0; s1++, s2++, --n)
+        if (*s1 != *s2)
+            return ((*(unsigned char *)s1 < *(unsigned char *)s2) ? -1 : 1);
+        else if (*s1 == '\0')
+            return 0;
+    return 0;
+}

photon/libc/string/strcpy.c

@@ -0,0 +1,26 @@
+char *strcpy(char *output, const char *input)
+{
+    unsigned int i;
+    for (i = 0; input[i] != 0; i++) {
+        output[i] = input[i];
+    }
+
+    output[i] = '\0';
+    return output;
+}
+
+char *strncpy(char *output, const char *input, unsigned int count)
+{
+    unsigned int size = count;
+    unsigned int i;
+    for (i = 0; i < size; i++) {
+        output[i] = input[i];
+
+        if (input[i] == 0) {
+            break;
+        }
+    }
+
+    output[i] = '\0';
+    return output;
+}

photon/libc/string/strdup.c

@@ -0,0 +1,11 @@
+#include <string.h>
+#include <stdlib.h>
+
+char *strdup(const char *str)
+{
+    size_t len = strlen(str);
+    char *out = malloc(len + 1);
+    memcpy(out, str, len);
+    out[len] = 0;
+    return out;
+}