Added some code

copy.c

@@ -1,24 +1,89 @@
-#include <stdio.h>
+#include <stdio.h>      /* fopen, fread, fwrite, fclose */
 #include <stdbool.h>
+#include <stdlib.h>     /* atexit */
 
 #include "fileinfo.h"
 #include "prodos.h"
 #include "cui.h"
 
+#define BUFFER_SIZE 2048
+
+void cleanup(void);
+FILE *openFile(const char *name, const char *mode);
+void closeFile(FILE *f, const char *name);
+void concatPath(char *dest, const char *src);
+
 char sourceName[PRODOS_PATH_MAX + 1];
 char destName[PRODOS_PATH_MAX + 1];
-FILE *sourceFile;
-FILE *destFile;
+FILE *sourceFile = NULL;
+FILE *destFile = NULL;
 struct FileInfo sourceInfo;
 struct FileInfo destInfo;
+size_t n;
+char buffer[BUFFER_SIZE];
+size_t bytesRead;
 
 void main(void)
 {
+    atexit(cleanup);
+
     inputFileName("Source file or directory:", sourceName, sizeof(sourceName), &sourceInfo);
     inputFileName("Destination file or directory:", destName, sizeof(destName), &destInfo);
 
-    sourceFile = fopen(sourceName, "r");
-    destFile = fopen(destName, "r");
+    sourceFile = openFile(sourceName, "r");
+
+    if (isDir(&destInfo)) {
+        concatPath(destName, basename(sourceName));
+    }
+
+    destFile = openFile(destName, "w");
+
+    while ((bytesRead = fread(buffer, 1, sizeof(buffer), sourceFile)) == BUFFER_SIZE) {
+        if (fwrite(buffer, 1, bytesRead, destFile) < bytesRead) {
+            perror(destName);
+            break;
+        }
+    }
+    if (bytesRead > 0 && !feof(destFile) && !ferror(destFile)) {
+        if (fwrite(buffer, 1, bytesRead, destFile) < bytesRead) {
+            perror(destName);
+        }
+    }
+    cleanup();
 }
 
+FILE *openFile(const char *name, const char *mode)
+{
+    FILE *f;
+    f = fopen(name, "r");
+    if (f == NULL) {
+        perror(name);
+        exit(EXIT_FAILURE);
+    }
+    return f;
+}
+
+void closeFile(FILE *f, const char *name)
+{
+    if (f != NULL) {
+        if (fclose(f) == EOF) {
+            perror(name);
+        }
+    }
+}
+
+void concatPath(char *dest, const char *src)
+{
+    size_t n;
+
+    n = PRODOS_PATH_MAX - strlen(dest);
+    strncat(dest, src, n);
+    dest[PRODOS_PATH_MAX] = '\0';
+}
+
+void cleanup(void)
+{
+    closeFile(destFile, destName);
+    closeFile(sourceFile, sourceName);
+}