Only print prompt in interactive usage

Scripting tftp(1) makes it non-interactive, yet the prompt is still
printed and may mess up the shell's PS1:
	$ echo put nonexistent | tftp localhost
	tftp> tftp: open: nonexistent: No such file or directory
	tftp> $

The fix seems easy and works as expected for multiple commands as well:
	$ echo 'verbose\nput nonexistent' | ./obj/tftp localhost
	Verbose mode on.
	tftp: open: nonexistent: No such file or directory
	$

OK millert

diff --git a/usr.bin/tftp/main.c b/usr.bin/tftp/main.c
index fe389c3..cbfdb07 100644 (file)
--- a/usr.bin/tftp/main.c
+++ b/usr.bin/tftp/main.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: main.c,v 1.43 2018/09/20 11:42:42 jsg Exp $   */
+/*     $OpenBSD: main.c,v 1.44 2022/10/04 07:03:27 kn Exp $    */
 /*     $NetBSD: main.c,v 1.6 1995/05/21 16:54:10 mycroft Exp $ */
 
 /*
@@ -602,7 +602,8 @@ command(void)
        struct cmd      *c;
 
        for (;;) {
-               printf("%s> ", prompt);
+               if (isatty(STDIN_FILENO))
+                       printf("%s> ", prompt);
                if (readcmd(line, LBUFLEN, stdin) < 1)
                        continue;
                if ((line[0] == 0) || (line[0] == '\n'))