During line editing, let Ctrl-C discard the current input line and

provide a fresh prompt instead of exiting the program.  This aligns
behaviour with bc(1), ftp(1), sftp(1), and all the shells.

OK naddy@

Both martijn@ and naddy@ point out that this program might profit
from signal handling during more of its code, but that would require
more code inspection, design work, and testing which i'm not planning
to do right now.  Consider standard behaviour during line editing
as a first step.

diff --git a/usr.bin/cdio/cdio.c b/usr.bin/cdio/cdio.c
index 0f82466..642900a 100644 (file)
--- a/usr.bin/cdio/cdio.c
+++ b/usr.bin/cdio/cdio.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: cdio.c,v 1.80 2021/01/18 00:44:00 mortimer Exp $      */
+/*     $OpenBSD: cdio.c,v 1.81 2021/08/13 10:56:54 schwarze Exp $      */
 
 /*  Copyright (c) 1995 Serge V. Vakulenko
  * All rights reserved.
@@ -63,6 +63,7 @@
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -158,6 +159,7 @@ int         verbose = 1;
 int            msf = 1;
 const char     *cddb_host;
 char           **track_names;
+volatile sig_atomic_t signo;
 
 EditLine       *el = NULL;     /* line-editing structure */
 History                *hist = NULL;   /* line-editing history */
@@ -179,6 +181,7 @@ int         pstatus(char *arg);
 int            play_next(char *arg);
 int            play_prev(char *arg);
 int            play_same(char *arg);
+void           sigint_handler(int);
 char           *input(int *);
 char           *prompt(void);
 void           prtrack(struct cd_toc_entry *e, int lastflag, char *name);
@@ -1499,18 +1502,36 @@ status(int *trk, int *min, int *sec, int *frame)
        return s.data->header.audio_status;
 }
 
+void
+sigint_handler(int signo_arg)
+{
+       signo = signo_arg;
+}
+
 char *
 input(int *cmd)
 {
+       struct sigaction sa;
        char *buf;
        int siz = 0;
        char *p;
        HistEvent hev;
 
+       memset(&sa, 0, sizeof(sa));
        do {
-               if ((buf = (char *) el_gets(el, &siz)) == NULL || !siz) {
-                       *cmd = CMD_QUIT;
+               signo = 0;
+               sa.sa_handler = sigint_handler;
+               if (sigaction(SIGINT, &sa, NULL) == -1)
+                       err(1, "sigaction");
+               buf = (char *)el_gets(el, &siz);
+               sa.sa_handler = SIG_DFL;
+               if (sigaction(SIGINT, &sa, NULL) == -1)
+                       err(1, "sigaction");
+               if (buf == NULL || siz <= 0) {
                        fprintf(stderr, "\r\n");
+                       if (siz < 0 && errno == EINTR && signo == SIGINT)
+                               continue;
+                       *cmd = CMD_QUIT;
                        return (0);
                }
                if (strlen(buf) > 1)