ttyread: test for EOF while reading tty

When a read operation returns 0 then it means that we arrived to the end of the
file, and new reads will return 0 unless you do some other operation such as
lseek(). This case happens with USB-232 adapters when they are unplugged.

1 files changed, 16 insertions, 9 deletions

diff --git a/st.c b/st.c
index 5f2352a..81973ee 100644
--- a/st.c
+++ b/st.c
@@ -823,17 +823,24 @@ ttyread(void)
         int ret;
 
         /* append read bytes to unprocessed bytes */
-        if ((ret = read(cmdfd, buf+buflen, LEN(buf)-buflen)) < 0)
-                die("couldn't read from shell: %s\n", strerror(errno));
-        buflen += ret;
+        ret = read(cmdfd, buf+buflen, LEN(buf)-buflen);
 
-        written = twrite(buf, buflen, 0);
-        buflen -= written;
-        /* keep any uncomplete utf8 char for the next call */
-        if (buflen > 0)
-                memmove(buf, buf + written, buflen);
+        switch (ret) {
+        case 0:
+                fputs("Found EOF in input\n", stderr);
+                exit(0);
+        case -1:
+                die("couldn't read from shell: %s\n", strerror(errno));
+        default:
+                buflen += ret;
+                written = twrite(buf, buflen, 0);
+                buflen -= written;
+                /* keep any uncomplete utf8 char for the next call */
+                if (buflen > 0)
+                        memmove(buf, buf + written, buflen);
+                return ret;
 
-        return ret;
+        }
 }
 
 void