Fix ttywrite()

[st.git] / st.c

diff --git a/st.c b/st.c
index 65a1866..900534b 100644 (file)
--- a/st.c
+++ b/st.c
@@ -415,7 +415,7 @@ static int32_t tdefcolor(int *, int *, int);
 static void tdeftran(char);
 static inline int match(uint, uint);
 static void ttynew(void);
-static void ttyread(void);
+static size_t ttyread(void);
 static void ttyresize(void);
 static void ttysend(char *, size_t);
 static void ttywrite(const char *, size_t);
@@ -1464,7 +1464,7 @@ ttynew(void)
        }
 }
 
-void
+size_t
 ttyread(void)
 {
        static char buf[BUFSIZ];
@@ -1489,14 +1489,16 @@ ttyread(void)
 
        /* keep any uncomplete utf8 char for the next call */
        memmove(buf, ptr, buflen);
+
+       return ret;
 }
 
 void
 ttywrite(const char *s, size_t n)
 {
-       fd_set wfd;
-       struct timespec tv;
+       fd_set wfd, rfd;
        ssize_t r;
+       size_t lim = 256;
 
        /*
         * Remember that we are using a pty, which might be a modem line.
@@ -1506,38 +1508,34 @@ ttywrite(const char *s, size_t n)
         */
        while (n > 0) {
                FD_ZERO(&wfd);
+               FD_ZERO(&rfd);
                FD_SET(cmdfd, &wfd);
-               tv.tv_sec = 0;
-               tv.tv_nsec = 0;
+               FD_SET(cmdfd, &rfd);
 
                /* Check if we can write. */
-               if (pselect(cmdfd+1, NULL, &wfd, NULL, &tv, NULL) < 0) {
+               if (pselect(cmdfd+1, &rfd, &wfd, NULL, NULL, NULL) < 0) {
                        if (errno == EINTR)
                                continue;
                        die("select failed: %s\n", strerror(errno));
                }
-               if(!FD_ISSET(cmdfd, &wfd)) {
-                       /* No, then free some buffer space. */
-                       ttyread();
-               } else {
+               if (FD_ISSET(cmdfd, &rfd))
+                       lim = ttyread();
+               if (FD_ISSET(cmdfd, &wfd)) {
                        /*
                         * Only write 256 bytes at maximum. This seems to be a
                         * reasonable value for a serial line. Bigger values
                         * might clog the I/O.
                         */
-                       r = write(cmdfd, s, (n < 256)? n : 256);
-                       if (r < 0) {
-                               die("write error on tty: %s\n",
-                                               strerror(errno));
-                       }
+                       if ((r = write(cmdfd, s, (n < 256)? n : 256)) < 0)
+                               goto write_error;
                        if (r < n) {
                                /*
                                 * We weren't able to write out everything.
                                 * This means the buffer is getting full
                                 * again. Empty it.
                                 */
-                               if (n < 256)
-                                       ttyread();
+                               if (n < lim)
+                                       lim = ttyread();
                                n -= r;
                                s += r;
                        } else {
@@ -1546,6 +1544,10 @@ ttywrite(const char *s, size_t n)
                        }
                }
        }
+       return;
+
+write_error:
+       die("write error on tty: %s\n", strerror(errno));
 }
 
 void