When the input files contain duplicates, then the rm fails. Because
duplicates occur most often when the * is used and the shell unwraps it.
There is a very common scenario when a user accidentally enters space
after a filename, or enters space instead of forward slash.
Example:
rm prefix_ *
The user intended to remove all files with a `prefix_` but removed all
of the files in cwd.
The program quits immediately when a duplicate is detected, to prevent
pressing `y` because user expected a prompt regarding removing multiple
files.
The force option disables this function to enable scripts to work
without modifying them.
```
diff --git a/src/rm.c b/src/rm.c
index 354e2b0df..e4f9949f0 100644
--- a/src/rm.c
+++ b/src/rm.c
@@ -123,6 +123,16 @@ diagnose_leading_hyphen (int argc, char **argv)
}
}
+static bool
+find_duplicates (int n_files, char **files)
+{
+ for (int l = 0; l < n_files-1; l++)
+ for (int r = l+1; r < n_files; r++)
+ if (strcmp(files[l], files[r]) == 0)
+ return true;
+ return false;
+}
+
void
usage (int status)
{
@@ -211,6 +221,7 @@ main (int argc, char **argv)
bool preserve_root = true;
struct rm_options x;
bool prompt_once = false;
+ bool force_rm = false;
int c;
initialize_main (&argc, &argv);
@@ -238,6 +249,7 @@ main (int argc, char **argv)
x.interactive = RMI_NEVER;
x.ignore_missing_files = true;
prompt_once = false;
+ force_rm = true;
break;
case 'i':
@@ -352,6 +364,17 @@ main (int argc, char **argv)
uintmax_t n_files = argc - optind;
char **file = argv + optind;
+ if (!force_rm && find_duplicates(n_files, file))
+ {
+ /* Because usually when the input files are duplicated it means
that the user
+ sumbitted both a directory and an * as separate arguments,
probably by accident */
+ fprintf (stderr,
+ "%s: input contains duplicates, most likely you've put "
+ "both * and a file from the same directory.\n",
+ program_name);
+ return EXIT_FAILURE;
+ }
+
if (prompt_once && (x.recursive || 3 < n_files))
{
fprintf (stderr,
```
