passsed all tests. ready for use now

README.md

@@ -1,5 +1,3 @@
-**This project is unfinished and NOT usable yet.**
-
 overlayfs-tools
 ========
 

logic.c

@@ -303,21 +303,20 @@ int merge_d(const char *lower_path, const char* upper_path, const size_t lower_r
                 }
                 return 0; // children must be recursed, and directory itself does not need to be printed
             }
-        } else { // other types of files
+        } else {
             command(script_stream, "rm %", lower_path);
         }
     }
     *fts_instr = FTS_SKIP;
-    return command(script_stream, "mv % %", upper_path, lower_path);
+    return command(script_stream, "mv -T % %", upper_path, lower_path);
 }
 
 int merge_dp(const char *lower_path, const char* upper_path, const size_t lower_root_len, const struct stat *lower_status, const struct stat *upper_status, bool verbose, FILE* script_stream, int *fts_instr) {
-    // if children ARE visited, delete the directory
     if (lower_status != NULL) {
         if (file_type(lower_status) == S_IFDIR) {
             bool opaque = false;
             if (is_opaquedir(upper_path, &opaque) < 0) { return -1; }
-            if (!opaque) {
+            if (!opaque) { // delete the directory: it should be empty already
                 return command(script_stream, "rmdir %", upper_path);
             }
         }
@@ -326,7 +325,7 @@ int merge_dp(const char *lower_path, const char* upper_path, const size_t lower_
 }
 
 int merge_f_sl(const char *lower_path, const char* upper_path, const size_t lower_root_len, const struct stat *lower_status, const struct stat *upper_status, bool verbose, FILE* script_stream, int *fts_instr) {
-    return command(script_stream, "mv % %", upper_path, lower_path);
+    return command(script_stream, "rm -rf %", lower_path) || command(script_stream, "mv -T % %", upper_path, lower_path);
 }
 
 int merge_whiteout(const char *lower_path, const char* upper_path, const size_t lower_root_len, const struct stat *lower_status, const struct stat *upper_status, bool verbose, FILE* script_stream, int *fts_instr) {

main.c

@@ -170,21 +170,24 @@ int main(int argc, char *argv[]) {
 
     if (optind == argc - 1) {
         int out;
-        char filename_template[] = "overylay-toolsXXXXXX.sh";
+        char filename_template[] = "overlay-tools-XXXXXX.sh";
         FILE *script = NULL;
         if (strcmp(argv[optind], "diff") == 0) {
             out = diff(lower, upper, verbose);
         } else if (strcmp(argv[optind], "vacuum") == 0) {
             script = create_shell_script(filename_template);
+            if (script == NULL) { fprintf(stderr, "Script file cannot be created."); return EXIT_FAILURE; }
             out = vacuum(lower, upper, verbose, script);
         } else if (strcmp(argv[optind], "merge") == 0) {
             script = create_shell_script(filename_template);
+            if (script == NULL) { fprintf(stderr, "Script file cannot be created."); return EXIT_FAILURE; }
             out = merge(lower, upper, verbose, script);
         } else {
             fprintf(stderr, "Action not supported.\n");
             goto see_help;
         }
         if (script != NULL) {
+            printf("The script %s is created. Run the script to do the actual work please. Remember to run it when the OverlayFS is not mounted.\n", filename_template);
             fclose(script);
         }
         if (out) {

sh.c

@@ -16,7 +16,7 @@ FILE* create_shell_script(char *tmp_path_buffer) {
     fprintf(f, "set -x\n");
     time_t rawtime;
     time (&rawtime);
-    fprintf(f, "# This sheel script is generated by overlayfs-tools on %s.\n", ctime (&rawtime));
+    fprintf(f, "# This shell script is generated by overlayfs-tools on %s\n", ctime (&rawtime));
     return f;
 }
 
@@ -39,12 +39,12 @@ int command(FILE *output, const char *command_format, ...) {
     for (size_t i = 0; command_format[i] != '\0'; i++) {
         if (command_format[i] == '%') {
             const char *s = va_arg(arg, char *);
-            if (quote(s, output) < 1) { return -1; }
+            if (quote(s, output) < 0) { return -1; }
         } else {
             if (fputc(command_format[i], output) == EOF) { return -1; }
         }
     }
     va_end(arg);
     if (fputc('\n', output) == EOF) { return -1; }
     return 0;
-}
+}