Add a warning whenever (de)compressing multiple files into one source, or into stdout

diff --git a/programs/fileio.c b/programs/fileio.c
index d5b8a7d143bd1cf2820a6d0f44c9b6cd89571f18..bdf42543b79c06943101accc26ee4e6432cb7f56 100644 (file)
--- a/programs/fileio.c
+++ b/programs/fileio.c
@@ -1677,6 +1677,29 @@ int FIO_compressMultipleFilenames(FIO_prefs_t* const prefs,
     /* init */
     assert(outFileName != NULL || suffix != NULL);
     if (outFileName != NULL) {   /* output into a single destination (stdout typically) */
+        if (nbFiles > 1) {
+            if (!strcmp (outFileName, stdoutmark)) {
+                DISPLAY("zstd: WARNING: all input files will be processed and concatenated into stdout. ");
+            } else {
+                DISPLAY("zstd: WARNING: all input files will be processed and concatenated into a single output file: %s ", outFileName);
+            }
+            if (prefs->removeSrcFile && !prefs->overwrite) {
+                DISPLAY("\nYou must specify -f as well in order to execute this command with --rm. Aborting...");
+                return 1;
+            }
+            
+            DISPLAY("Proceed? (y/n): ");
+            {
+                int ch = getchar();
+                if ((ch != 'y') && (ch != 'Y')) {
+                    DISPLAY("zstd: aborting...\n");
+                    return 1;
+                }
+                /* flush the rest */
+                while ((ch!=EOF) && (ch!='\n'))
+                    ch = getchar();
+            }
+        }
         ress.dstFile = FIO_openDstFile(prefs, NULL, outFileName);
         if (ress.dstFile == NULL) {  /* could not open outFileName */
             error = 1;

diff --git a/tests/playTests.sh b/tests/playTests.sh
index b7bfa76cde95ab91b28a21684e2eccb35c92ea40..b84cffd014596e0284c6ec56081c9727b9711e5a 100755 (executable)
--- a/tests/playTests.sh
+++ b/tests/playTests.sh
@@ -349,19 +349,25 @@ rm tmp*
 println "\n===>  compress multiple files"
 println hello > tmp1
 println world > tmp2
-zstd tmp1 tmp2 -o "$INTOVOID" -f
-zstd tmp1 tmp2 -c | zstd -t
-zstd tmp1 tmp2 -o tmp.zst
+echo 'y' | zstd tmp1 tmp2 -o "$INTOVOID" -f  # echo 'y' confirms the warning prompt
+echo 'y' | zstd tmp1 tmp2 -c | zstd -t
+echo 'y' | zstd tmp1 tmp2 -o tmp.zst
 test ! -f tmp1.zst
 test ! -f tmp2.zst
 zstd tmp1 tmp2
 zstd -t tmp1.zst tmp2.zst
 zstd -dc tmp1.zst tmp2.zst
-zstd tmp1.zst tmp2.zst -o "$INTOVOID" -f
-zstd -d tmp1.zst tmp2.zst -o tmp
+echo 'y' | zstd tmp1.zst tmp2.zst -o "$INTOVOID" -f
+echo 'y' | zstd -d tmp1.zst tmp2.zst -o tmp
 touch tmpexists
-zstd tmp1 tmp2 -f -o tmpexists
-zstd tmp1 tmp2 -o tmpexists && die "should have refused to overwrite"
+echo 'y' | zstd tmp1 tmp2 -f -o tmpexists
+echo 'y' | zstd tmp1 tmp2 -o tmpexists && die "should have refused to overwrite"
+zstd tmp1 tmp2 -o "$INTOVOID" --rm && die "should have refused to execute with --rm"
+println gooder > tmp_rm1
+println boi > tmp_rm2
+echo 'y' | zstd tmp_rm1 tmp_rm2 -o tmp_rm3.zst -f --rm
+rm tmp_rm3.zst
+
 # Bug: PR #972
 if [ "$?" -eq 139 ]; then
   die "should not have segfaulted"
@@ -382,7 +388,7 @@ test -f tmp1
 test -f tmp2
 test -f tmp3
 println "compress tmp* into stdout > tmpall : "
-zstd -c tmp1 tmp2 tmp3 > tmpall
+echo 'y' | zstd -c tmp1 tmp2 tmp3 > tmpall
 test -f tmpall  # should check size of tmpall (should be tmp1.zst + tmp2.zst + tmp3.zst)
 println "decompress tmpall* into stdout > tmpdec : "
 cp tmpall tmpall2
@@ -920,7 +926,7 @@ datagen | zstd -c | zstd -t
 println "\n===>  golden files tests "
 
 zstd -t -r "$TESTDIR/golden-decompression"
-zstd -c -r "$TESTDIR/golden-compression" | zstd -t
+echo 'y' | zstd -c -r "$TESTDIR/golden-compression" | zstd -t
 zstd -D "$TESTDIR/golden-dictionaries/http-dict-missing-symbols" "$TESTDIR/golden-compression/http" -c | zstd -D "$TESTDIR/golden-dictionaries/http-dict-missing-symbols" -t