1 files changed, 88 insertions, 0 deletions
diff --git a/c/src/main.c b/c/src/main.c
new file mode 100644
index 0000000..1b9afcd
--- /dev/null
+++ b/c/src/main.c
@@ -0,0 +1,88 @@
+#include <assert.h>
+#include <stdio.h>
+#include <sys/types.h>
+
+#include <stdlib.h>
+
+#include <readline/readline.h>
+#include <readline/rlconf.h>
+
+#include <libgen.h>
+#include <stdbool.h>
+#include <unistd.h>
+
+#include "rename.h"
+
+bool file_exists(const char *filename) { return (access(filename, F_OK) == 0); }
+
+char *update_file_name(char *old_file_name, FILE *newin) {
+  fprintf(newin, "%s", old_file_name);
+
+  char *new_file_name = readline("New name: ");
+
+  return new_file_name;
+}
+
+bool ask_for_confirmation(char *prompt) {
+  bool return_value = false;
+  char *confirmation = readline(prompt);
+
+  if (strcmp(confirmation, "y") == 0)
+    return_value = true;
+
+  free(confirmation);
+  return return_value;
+}
+
+int main() {
+  const char *newin_name = tempnam(NULL, NULL);
+  FILE *newin = fopen(newin_name, "w");
+  if (!newin)
+    perror("Failed to create tempfile");
+  FILE *_ = freopen(newin_name, "r", stdin);
+
+  char *old_file_name = getenv("f");
+  old_file_name = basename(old_file_name);
+  char *new_file_name = (char *)NULL;
+  char *current_file_name = (char *)malloc(sizeof(char) * 255);
+  const char *original_file_name = getenv("f");
+
+  int done = false;
+
+  while (!done) {
+    if (old_file_name) {
+      new_file_name = update_file_name(old_file_name, newin);
+      old_file_name = (char *)NULL;
+    } else {
+      new_file_name = update_file_name(current_file_name, newin);
+    }
+    if (file_exists(new_file_name)) {
+      char *prompt = malloc(sizeof(char) * (255 + 43));
+      snprintf(prompt, 43 + 255,
+               "Name (`%s`) already exists, overwrite [y|N]: ", new_file_name);
+      if (ask_for_confirmation(prompt))
+        done = true;
+      free(prompt);
+    } else if (new_file_name[0] == '\0') {
+      /* new_file_name is emtpy */
+      if (ask_for_confirmation("Name is empty, accept nevertheless [y|N]: "))
+        done = true;
+    } else {
+      done = true;
+    }
+    if (!done) {
+      strcpy(current_file_name, new_file_name);
+      free(new_file_name);
+      new_file_name = (char *)NULL;
+    }
+  }
+
+  // rename old file with new name
+  if (rename(original_file_name, new_file_name) == 0) {
+    printf("File renamed successfully.\n");
+  } else {
+    perror("Unable to rename files. Please check files exist and you have "
+           "permissions to modify files");
+  }
+  free(new_file_name);
+}