lab6

lab6/main.c

@@ -0,0 +1,145 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#define buffer_size 1048576 // 1Mb
+
+typedef struct file_metadata
+{
+    int file_size;
+    char *file_name;
+} file_metadata;
+
+void create_arc(char *arc_name, int argc, char *argv[])
+{
+    FILE *fout = fopen(arc_name, "wb");
+    char n = argc - 4;
+    fputc(n, fout);
+
+    for (int i = 4; i < argc; i++)
+    {
+        FILE *fin = fopen(argv[i], "rb");
+
+        char name_length = strlen(argv[i]);
+        fputc(name_length, fout);
+
+        int file_size;
+        fseek(fin, 0, SEEK_END);
+        file_size = ftell(fin);
+        fseek(fin, 0, SEEK_SET);
+        fwrite(&file_size, sizeof(int), 1, fout);
+
+        fwrite(argv[i], 1, name_length, fout);
+
+        char *data = (char *)malloc(file_size);
+        fread(data, 1, file_size, fin);
+        fwrite(data, 1, file_size, fout);
+
+        free(data);
+        fclose(fin);
+    }
+    fclose(fout);
+}
+
+file_metadata get_file_metadata(FILE *fin)
+{
+    char name_length;
+    fread(&name_length, 1, 1, fin);
+
+    int file_size;
+    fread(&file_size, sizeof(int), 1, fin);
+
+    char *file_name = (char *)malloc(name_length + 1);
+    file_name[name_length] = '\0';
+
+    fread(file_name, 1, name_length, fin);
+
+    file_metadata data;
+    data.file_size = file_size;
+    data.file_name = file_name;
+
+    return data;
+}
+
+void get_list(char *arc_name)
+{
+    FILE *arc = fopen(arc_name, "rb");
+    char n;
+    fread(&n, 1, 1, arc);
+
+    for (int i = 0; i < n; i++)
+    {
+        file_metadata metadata = get_file_metadata(arc);
+
+        fseek(arc, metadata.file_size, SEEK_CUR);
+        printf("%s ", metadata.file_name);
+        free(metadata.file_name);
+    }
+    fclose(arc);
+}
+
+void extract_arc(char *arc_name)
+{
+    FILE *arc = fopen(arc_name, "rb");
+    char n;
+    fread(&n, 1, 1, arc);
+
+    for (int i = 0; i < n; i++)
+    {
+        file_metadata metadata = get_file_metadata(arc);
+
+        FILE *out = fopen(metadata.file_name, "wb");
+        char buffer[buffer_size];
+        int mod = metadata.file_size;
+        while (mod > buffer_size)
+        {
+            fread(&buffer, 1, buffer_size, arc);
+            fwrite(&buffer, 1, buffer_size, out);
+            mod -= buffer_size;
+        }
+        fread(&buffer, 1, mod, arc);
+        fwrite(&buffer, 1, mod, out);
+
+        free(metadata.file_name);
+        fclose(out);
+    }
+    fclose(arc);
+}
+
+int main(int argc, char *argv[])
+{
+    if (argc < 4)
+    {
+        printf("Error, not enough arguments\n");
+        return -1;
+    }
+
+    char *arc_name;
+
+    for (int i = 1; i < 4; i += 2)
+    {
+        if (strcmp(argv[i], "--file") == 0)
+        {
+            arc_name = argv[i + 1];
+        }
+        else if (strcmp(argv[i], "--create") == 0)
+        {
+            create_arc(arc_name, argc, argv);
+        }
+        else if (strcmp(argv[i], "--extract") == 0)
+        {
+            extract_arc(arc_name);
+        }
+        else if (strcmp(argv[i], "--list") == 0)
+        {
+            get_list(arc_name);
+        }
+        else
+        {
+            printf("Error, wrong format\n");
+            return -1;
+        }
+    }
+
+    return 0;
+}