Remove hard-coded 80 column output

When stdout is detected to be a tty use the number of columns
specified by the terminal.  If that fails fall back to a default
80 column width.  In the non-tty case allow for 999 column lines.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

diff --git a/cmd/zpool/zpool_main.c b/cmd/zpool/zpool_main.c
index 9e73dda..5dbb119 100644 (file)
--- a/cmd/zpool/zpool_main.c
+++ b/cmd/zpool/zpool_main.c
@@ -2175,11 +2175,30 @@ print_iostat(zpool_handle_t *zhp, void *data)
        return (0);
 }
 
+static int
+get_columns(void)
+{
+       struct winsize ws;
+       int columns = 80;
+       int error;
+
+       if (isatty(STDOUT_FILENO)) {
+               error = ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws);
+               if (error == 0)
+                       columns = ws.ws_col;
+       } else {
+               columns = 999;
+       }
+
+       return columns;
+}
+
 int
 get_namewidth(zpool_handle_t *zhp, void *data)
 {
        iostat_cbdata_t *cb = data;
        nvlist_t *config, *nvroot;
+       int columns;
 
        if ((config = zpool_get_config(zhp, NULL)) != NULL) {
                verify(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
@@ -2191,13 +2210,15 @@ get_namewidth(zpool_handle_t *zhp, void *data)
        }
 
        /*
-        * The width must fall into the range [10,38].  The upper limit is the
-        * maximum we can have and still fit in 80 columns.
+        * The width must be at least 10, but may be as large as the
+        * column width - 42 so that we can still fit in one line.
         */
+       columns = get_columns();
+
        if (cb->cb_namewidth < 10)
                cb->cb_namewidth = 10;
-       if (cb->cb_namewidth > 38)
-               cb->cb_namewidth = 38;
+       if (cb->cb_namewidth > columns - 42)
+               cb->cb_namewidth = columns - 42;
 
        return (0);
 }