♻ Extract command line args parsing into separate function

.vscode/settings.json

@@ -6,7 +6,8 @@
     "decryptutilities.h": "c",
     "fileutilities.h": "c",
     "stdio.h": "c",
-    "stdlib.h": "c"
+    "stdlib.h": "c",
+    "stdbool.h": "c"
   },
   "cSpell.words": [
     "init",

src/main.c

@@ -1,4 +1,3 @@
-#include <getopt.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -9,6 +8,7 @@
 #include "decrypt.h"
 #include "fileReader.h"
 #include "inflate.h"
+#include "parseArguments.h"
 #include "utils/min.h"
 
 #define BUFFER_SIZE 512UL * 1024UL //512 KiB
@@ -26,84 +26,9 @@ uint32_t getUint32(uint8_t* buffer) {
     (uint32_t)buffer[3] << 24;
 }
 
-struct arguments {
-  /** Path to the disk file that contains the start of the file we want to extract.
-   * The file may stretch across multiple disks though.
-   */
-  char* diskName;
-  /** Offset into the disk where the file starts. */
-  unsigned long diskOffset;
-  /** Size of the file stored in the disk. */
-  unsigned long fileSize;
-  //Decryption keys
-  bool isEncrypted;
-  //For xdelta3, the location of the old file
-  char* prevFile;
-};
-
-static struct option long_options[] = {
-  {"disk", required_argument, 0, 'd'},
-  {"offset", required_argument, 0, 'o'},
-  {"size", required_argument, 0, 's'},
-  {"keys", required_argument, 0, 'k'},
-  {"prev", required_argument, 0, 'p'},
-};
-
-//Stores current state from command line arguments, initialized to zero
-struct arguments state = {};
-
 int main(int argc, char *argv[]) {
   //Parse command line arguments
-
-  int requiredOptions = 0;
-
-  while (1) {
-    //in this variable, getopt_long stores the current position in the command line args array
-    int option_index = 0;
-
-    int curOption = getopt_long(argc, argv, "d:o:s:k:p:", long_options, &option_index);
-
-    //end of command line arguments reached
-    if (curOption == -1) {
-      break;
-    }
-
-    switch (curOption) {
-      case 'd': //disk name
-        state.diskName = optarg;
-        requiredOptions |= 1;
-        break;
-      case 'o': //offset
-        state.diskOffset = atol(optarg);
-        requiredOptions |= 2;
-        break;
-      case 's': //size
-        state.fileSize = atol(optarg);
-        requiredOptions |= 4;
-        break;
-      case 'k': { //decryption keys
-        //TODO: parse from optarg
-        uint32_t key0 = atoi(argv[8]);
-        uint32_t key1 = atoi(argv[9]);
-        uint32_t key2 = atoi(argv[10]);
-        //Initialize decryption (pass decryption keys)
-        initDecryptor(key0, key1, key2);
-        state.isEncrypted = true;
-        break;
-      }
-      case 'p': //prev file for xdelta3
-        //TODO
-        break;
-      default:
-        fprintf(stderr, "Unknown option '%c'.", (char)curOption);
-        exit(1);
-    }
-  }
-
-  if (requiredOptions != 7) {
-    fprintf(stderr, "Missing arguments, received %i.", requiredOptions);
-    exit(1);
-  }
+  struct arguments state = parseArguments(argc, argv);
 
   //-------------------------------------------------
 

src/parseArguments.c

@@ -0,0 +1,72 @@
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "decrypt.h"
+#include "parseArguments.h"
+
+static struct option long_options[] = {
+  {"disk", required_argument, 0, 'd'},
+  {"offset", required_argument, 0, 'o'},
+  {"size", required_argument, 0, 's'},
+  {"keys", required_argument, 0, 'k'},
+  {"prev", required_argument, 0, 'p'},
+};
+
+
+struct arguments parseArguments(int argc, char *argv[]) {
+  //Stores current state from command line arguments, initialized to zero
+  struct arguments state = {};
+
+  int requiredOptions = 0;
+
+  while (1) {
+    //in this variable, getopt_long stores the current position in the command line args array
+    int option_index = 0;
+
+    int curOption = getopt_long(argc, argv, "d:o:s:k:p:", long_options, &option_index);
+
+    //end of command line arguments reached
+    if (curOption == -1) {
+      break;
+    }
+
+    switch (curOption) {
+      case 'd': //disk name
+        state.diskName = optarg;
+        requiredOptions |= 1;
+        break;
+      case 'o': //offset
+        state.diskOffset = atol(optarg);
+        requiredOptions |= 2;
+        break;
+      case 's': //size
+        state.fileSize = atol(optarg);
+        requiredOptions |= 4;
+        break;
+      case 'k': { //decryption keys
+        //TODO: parse from optarg
+        uint32_t key0 = atoi(argv[8]);
+        uint32_t key1 = atoi(argv[9]);
+        uint32_t key2 = atoi(argv[10]);
+        //Initialize decryption (pass decryption keys)
+        initDecryptor(key0, key1, key2);
+        state.isEncrypted = true;
+        break;
+      }
+      case 'p': //prev file for xdelta3
+        //TODO
+        break;
+      default:
+        fprintf(stderr, "Unknown option '%c'.", (char)curOption);
+        exit(1);
+    }
+  }
+
+  if (requiredOptions != 7) {
+    fprintf(stderr, "Missing arguments, received %i.", requiredOptions);
+    exit(1);
+  }
+
+  return state;
+}

src/parseArguments.h

@@ -0,0 +1,19 @@
+#include <stdbool.h>
+
+struct arguments {
+  /** Path to the disk file that contains the start of the file we want to extract.
+   * The file may stretch across multiple disks though.
+   */
+  char* diskName;
+  /** Offset into the disk where the file starts. */
+  unsigned long diskOffset;
+  /** Size of the file stored in the disk. */
+  unsigned long fileSize;
+  //Decryption keys
+  bool isEncrypted;
+  //For xdelta3, the location of the old file
+  char* prevFile;
+};
+
+
+struct arguments parseArguments(int argc, char *argv[]);