rename: detect tty in cbreak mode to make ask() read a single byte

Set tty_cbreak only when tty has a VMIN of 1 to avoid having to purge at
all in cbreak mode.

The prompt is still compatible with a non interactive input from a pipe.

diff --git a/misc-utils/rename.c b/misc-utils/rename.c
index d98e9d8f9079be881224231ed011f7bbe04aed7e..1c24d7e32969315f1a50f7e4765be6e70ddbbb0e 100644 (file)
--- a/misc-utils/rename.c
+++ b/misc-utils/rename.c
@@ -20,6 +20,7 @@ for i in $@; do N=`echo "$i" | sed "s/$FROM/$TO/g"`; mv "$i" "$N"; done
 #include <getopt.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <termios.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 
@@ -33,6 +34,8 @@ for i in $@; do N=`echo "$i" | sed "s/$FROM/$TO/g"`; mv "$i" "$N"; done
 #define RENAME_EXIT_NOTHING    4
 #define RENAME_EXIT_UNEXPLAINED        64
 
+static int tty_cbreak = 0;
+
 static int string_replace(char *from, char *to, char *s, char *orig, char **newname)
 {
        char *p, *q, *where;
@@ -68,7 +71,9 @@ static int ask(char *name)
        }
        else {
                buf[0] = c; buf[1] = '\0';
-               if (c != '\n')
+               if (c != '\n' && tty_cbreak) /* no purge necessary */
+                       printf("\n");
+               else if (c != '\n')
                        while ((c = fgetc(stdin)) != '\n' && c != EOF);
        }
        if (rpmatch(buf) == RPMATCH_YES)
@@ -202,6 +207,7 @@ int main(int argc, char **argv)
 {
        char *from, *to;
        int i, c, ret = 0, verbose = 0, noact = 0, nooverwrite = 0, interactive = 0;
+       struct termios tio;
        int (*do_rename)(char *from, char *to, char *s, int verbose, int noact,
                         int nooverwrite, int interactive) = do_file;
 
@@ -263,6 +269,14 @@ int main(int argc, char **argv)
        if (!strcmp(from, to))
                return RENAME_EXIT_NOTHING;
 
+       tty_cbreak = 0;
+       if (interactive && isatty(STDIN_FILENO) != 0) {
+               if (tcgetattr(STDIN_FILENO, &tio) != 0)
+                       warn(_("failed to get terminal attributes"));
+               else if (!(tio.c_lflag & ICANON) && tio.c_cc[VMIN] == 1)
+                       tty_cbreak = 1;
+       }
+
        for (i = 2; i < argc; i++)
                ret |= do_rename(from, to, argv[i], verbose, noact, nooverwrite, interactive);