tools/gpgtar: Add '--dry-run'.

* tools/gpgtar-extract.c (extract_{regular,directory}): Honor
'--dry-run'.
* tools/gpgtar.c (enum cmd_and_opt_values): New value.
(opts): Add '--dry-run'.
(parse_arguments): Handle '--dry-run'.
* tools/gpgtar.h (opt): Add field 'dry_run'.

Signed-off-by: Justus Winter <justus@g10code.com>

tools/gpgtar-extract.c

@@ -53,7 +53,10 @@ extract_regular (estream_t stream, const char *dirname,
   else
     err = 0;
 
-  outfp = es_fopen (fname, "wb");
+  if (opt.dry_run)
+    outfp = es_fopenmem (0, "wb");
+  else
+    outfp = es_fopen (fname, "wb");
   if (!outfp)
     {
       err = gpg_error_from_syserror ();
@@ -120,7 +123,7 @@ extract_directory (const char *dirname, tar_header_t hdr)
 
  /* Note that we don't need to care about EEXIST because we always
      extract into a new hierarchy.  */
-  if (gnupg_mkdir (fname, "-rwx------"))
+  if (! opt.dry_run && gnupg_mkdir (fname, "-rwx------"))
     {
       err = gpg_error_from_syserror ();
       if (gpg_err_code (err) == GPG_ERR_ENOENT)

tools/gpgtar.c

@@ -77,6 +77,9 @@ enum cmd_and_opt_values
     /* Compatibility with gpg-zip.  */
     oGpgArgs,
     oTarArgs,
+
+    /* Debugging.  */
+    oDryRun,
   };
 
 
@@ -100,6 +103,7 @@ static ARGPARSE_OPTS opts[] = {
   ARGPARSE_s_n (oQuiet,	"quiet",  N_("be somewhat more quiet")),
   ARGPARSE_s_s (oGpgProgram, "gpg", "@"),
   ARGPARSE_s_n (oSkipCrypto, "skip-crypto", N_("skip the crypto processing")),
+  ARGPARSE_s_n (oDryRun, "dry-run", N_("do not make any changes")),
   ARGPARSE_s_s (oSetFilename, "set-filename", "@"),
   ARGPARSE_s_n (oOpenPGP, "openpgp", "@"),
   ARGPARSE_s_n (oCMS, "cms", "@"),
@@ -377,6 +381,10 @@ parse_arguments (ARGPARSE_ARGS *pargs, ARGPARSE_OPTS *popts)
             }
           break;
 
+        case oDryRun:
+          opt.dry_run = 1;
+          break;
+
         default: pargs->err = 2; break;
 	}
     }

tools/gpgtar.h

@@ -29,6 +29,7 @@ struct
   int verbose;
   unsigned int debug_level;
   int quiet;
+  int dry_run;
   const char *gpg_program;
   strlist_t gpg_arguments;
   const char *outfile;