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.

diff --git a/st.c b/st.c
index 5f2352a..81973ee 100644 (file)
--- 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