Handle terminal resizing.

1 files changed, 57 insertions, 7 deletions

diff --git a/pw.c b/pw.c
index a7c62d4..8bb2184 100644
--- a/pw.c
+++ b/pw.c
@@ -74,6 +74,8 @@ static unsigned ncmdhist;
 static char **pathist;
 static unsigned npathist;
 
+volatile sig_atomic_t winch;
+
 static void panic(const char *fmt, ...)
 {
   va_list vl;
@@ -520,11 +522,26 @@ static void ttyget(int fd, struct termios *tty)
     panic("unable to get TTY parameters");
 }
 
+static void sigwinch(int sig)
+{
+  (void) sig;
+  winch = 1;
+}
+
+static char **resizebuf(char **buf, size_t nlfrom, size_t nlto)
+{
+  if ((buf = realloc(buf, sizeof *buf * nlto)) == 0)
+    panic("out of memory");
+  if (nlfrom < nlto)
+    memset(buf + nlfrom, 0, (nlto - nlfrom) * sizeof *buf);
+  return buf;
+}
+
 int main(int argc, char **argv)
 {
   char *line = 0;
   FILE *tty = fopen("/dev/tty", "r+");
-  int maxlines = 15, nlines = 0;
+  int maxlines = 15, nlines = 0, maxed = 0;
   int opt;
   int fd = fileno(stdin);
   int ttyfd = tty ? fileno(tty) : -1;
@@ -539,6 +556,9 @@ int main(int argc, char **argv)
   int auto_quit = 1;
   int exit_status = EXIT_FAILURE;
   char cmdbuf[cmdsize], *curcmd = 0, *savedcmd = 0;
+#ifdef SIGWINCH
+  static struct sigaction sa;
+#endif
 
   if (fd < 0)
     panic("unable to obtain input file descriptor");
@@ -599,8 +619,10 @@ int main(int argc, char **argv)
   }
 
   if (ioctl(ttyfd, TIOCGWINSZ, &ws) == 0 && ws.ws_row != 0) {
-    if (maxlines >= ws.ws_row)
+    if (maxlines >= ws.ws_row) {
       maxlines = ws.ws_row - 1;
+      maxed = 1;
+    }
     columns = ws.ws_col;
   }
 
@@ -622,6 +644,11 @@ int main(int argc, char **argv)
   if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
     panic("unable to set stdin nonblocking");
 
+#ifdef SIGWINCH
+  sa.sa_handler = sigwinch;
+  sigaction(SIGWINCH, &sa, NULL);
+#endif
+
   for (unsigned stat = stat_dirty, hpos = 0,
                 kbd_state = kbd_cmd, kbd_prev = kbd_cmd, lasttime = ~0U,
                 work = 1000, histpos = 0;
@@ -695,6 +722,30 @@ int main(int argc, char **argv)
       nfds = 1;
     }
 
+    if (winch) {
+      winch = 0;
+      if (ioctl(ttyfd, TIOCGWINSZ, &ws) == 0) {
+        if (maxed) {
+          circbuf = resizebuf(circbuf, maxlines, ws.ws_row - 1);
+          snapshot = resizebuf(snapshot, maxlines, ws.ws_row - 1);
+          maxlines = ws.ws_row - 1;
+        } else {
+          if (maxlines >= ws.ws_row) {
+            maxlines = ws.ws_row - 1;
+            maxed = 1;
+          }
+        }
+
+        if (nlines > maxlines)
+          nlines = maxlines;
+        if (snaplines > maxlines)
+          snaplines = maxlines;
+
+        columns = ws.ws_col;
+      }
+      force = 1;
+    }
+
     if ((stat & stat_eof))
       pollms = -1;
     else if (nfds < 2)
@@ -815,12 +866,11 @@ int main(int argc, char **argv)
           case '+':
             if (ws.ws_row && maxlines >= ws.ws_row - 1)
               break;
+            circbuf = resizebuf(circbuf, maxlines, maxlines + 1);
+            snapshot = resizebuf(snapshot, maxlines, maxlines + 1);
             maxlines++;
-            if ((circbuf = realloc(circbuf, sizeof *circbuf * maxlines)) == 0)
-              panic("out of memory");
-            if ((snapshot = realloc(snapshot, sizeof *snapshot * maxlines)) == 0)
-              panic("out of memory");
-            snapshot[maxlines-1] = circbuf[maxlines-1] = 0;
+            if (maxlines == ws.ws_row - 1)
+              maxed = 1;
             break;
           }
           break;