TAR COMPATIBILITYYYYYYYYYYYY

epitar/src/tar/archive.c

@@ -1,8 +1,11 @@
 #include "archive.h"
 
+#include <grp.h>
+#include <pwd.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <string.h>
+#include <sys/stat.h>
 
 #include "../utils/filesystem.h"
 #include "tar.h"
@@ -32,31 +35,55 @@ static struct ustar_header create_header(FILE *file_stream, char *file_path)
     // Versions
     memcpy(header.version, TVERSION, TVERSLEN);
 
-    // TODO handle uid, gid, mtime, and links
+    // uid, gid, mtime and mode
+    struct stat st;
+    if (stat(file_path, &st) == -1)
+    {
+        printf("Could not stat file %s\n", file_path);
+        return header;
+    }
+    // TODO links
+    // UID
+    snprintf(header.uid, sizeof(header.uid), "%07o", st.st_uid);
+    // GID
+    snprintf(header.gid, sizeof(header.gid), "%07o", st.st_gid);
+    // Mtime
+    snprintf(header.mtime, sizeof(header.mtime), "%011lo", st.st_mtime);
+    // Mode
+    snprintf(header.mode, sizeof(header.mode), "%07o", st.st_mode & 0777);
+
+    // User name
+    struct passwd *pw = getpwuid(st.st_uid);
+    if (pw != NULL)
+        strncpy(header.uname, pw->pw_name, 32);
+    // Group name
+    struct group *gr = getgrgid(st.st_gid);
+    if (gr != NULL)
+        strncpy(header.gname, gr->gr_name, 32);
 
     // File or directory
     if (file_stream == NULL)
     {
         // === Directory
+        header.name[strlen(header.name)] = '/';
         // Type
         header.typeflag = DIRTYPE;
+        // Size
+        snprintf(header.size, 12, "%011o", 0);
     }
     else
     {
         // === File
-        //  Length
+        //  Size
-        size_t file_size = getfilesize(file_stream);
+        snprintf(header.size, 12, "%011lo", st.st_size);
-        snprintf(header.size, TSIZELEN, "%lu", file_size);
         // Type
         header.typeflag = REGTYPE;
     }
 
     // Checksum
     union tar_header header_union = { .ustar = header };
-    size_t chksum = compute_checksum(&header_union);
+    compute_checksum(&header_union);
-    snprintf(header.chksum, TCHKSUMLEN, "%lu", chksum);
+    return header_union.ustar;
-
-    return header;
 }
 
 /**
@@ -118,7 +145,7 @@ static enum error_code archivedir(FILE *archive, char *dir_path, bool verbose)
 {
     // Add the directory itself
     if (verbose)
-        puts(dir_path);
+        printf("%s/\n", dir_path);
 
     // Header
     struct ustar_header header = create_header(NULL, dir_path);

epitar/src/tar/tar.c

@@ -1,6 +1,6 @@
 #include "tar.h"
 
-#include <stdlib.h>
+#include <stdio.h>
 #include <string.h>
 
 struct unixtar_header *get_unixtar_header(union tar_header *header)
@@ -26,34 +26,58 @@ bool check_checksum(union tar_header *header)
 {
     struct ustar_header *ustar_header;
     struct unixtar_header *unixtar_header;
-    int actual_checksum;
+    char actual_checksum[TCHKSUMLEN];
 
     // USTAR
     if ((ustar_header = get_ustar_header(header)) != NULL)
     {
-        actual_checksum = atoi(ustar_header->chksum);
+        strcpy(actual_checksum, ustar_header->chksum);
+        return strcmp(actual_checksum, header->ustar.chksum) == 0;
     }
     // UNIXTAR
     else if ((unixtar_header = get_unixtar_header(header)) != NULL)
     {
-        actual_checksum = atoi(unixtar_header->chksum);
+        strcpy(actual_checksum, unixtar_header->chksum);
+        return strcmp(actual_checksum, header->unixtar.chksum) == 0;
     }
     // Unsupported format
     else
     {
         return false;
     }
-
-    int computed_checksum = compute_checksum(header);
-    return computed_checksum == actual_checksum;
 }
 
-int compute_checksum(union tar_header *header)
+void compute_checksum(union tar_header *header)
 {
-    char *block = header->raw_block;
+    // Set to spaces
-    int sum = 0;
+    struct unixtar_header *unixtar_header = get_unixtar_header(header);
+    struct ustar_header *ustar_header = get_ustar_header(header);
+    if (ustar_header)
+    {
+        memset(ustar_header->chksum, ' ', TCHKSUMLEN);
+    }
+    else if (unixtar_header)
+    {
+        memset(unixtar_header->chksum, ' ', TCHKSUMLEN);
+    }
+
+    // Compute
+    unsigned char *block = header->raw_block;
+    unsigned int sum = 0;
     for (int i = 0; i < BLOCK_SIZE; i++)
         sum += block[i];
 
-    return sum;
+    // Update checksum
+    if (ustar_header)
+    {
+        snprintf(ustar_header->chksum, TCHKSUMLEN - 1, "%06o", sum);
+        ustar_header->chksum[TCHKSUMLEN - 2] = '\0';
+        ustar_header->chksum[TCHKSUMLEN - 1] = ' ';
+    }
+    else if (unixtar_header)
+    {
+        snprintf(unixtar_header->chksum, TCHKSUMLEN - 1, "%06o", sum);
+        unixtar_header->chksum[TCHKSUMLEN - 2] = '\0';
+        unixtar_header->chksum[TCHKSUMLEN - 1] = ' ';
+    }
 }

epitar/src/tar/tar.h

@@ -86,7 +86,7 @@ union tar_header
 {
     struct unixtar_header unixtar;
     struct ustar_header ustar;
-    char raw_block[BLOCK_SIZE];
+    unsigned char raw_block[BLOCK_SIZE];
 };
 
 // === Functions
@@ -103,13 +103,14 @@ struct unixtar_header *get_unixtar_header(union tar_header *header);
 struct ustar_header *get_ustar_header(union tar_header *header);
 
 /* @brief checks if file has not been corrupted via checksum
+ * @warn Alters header checksum with the new one
  * @return true if member file is valid, false otherwise
  */
 bool check_checksum(union tar_header *header);
 
-/* @brief computes the checksum of the given file
+/* @brief computes the checksum of the given header and updates it
  * @return the checksum
  */
-int compute_checksum(union tar_header *header);
+void compute_checksum(union tar_header *header);
 
 #endif // TAR_H

epitar/src/utils/errors.h

@@ -14,6 +14,7 @@ enum error_code
     TARGET_ALREADY_EXISTS,
     NO_TARGET_PROVIDED,
     EMPTY_ARCHIVE,
+    CANNOT_STAT,
     NOT_IMPLEMENTED
 };