[Mesa-dev] [PATCH] aubinator: Use less -RS instead of -r for the implicit pager.

[Kenneth Graunke]

>From the less man page:

   "Warning: when the -r option is used, less cannot keep track of the
    actual appearance  of  the screen (since this depends  on  how the
    screen responds to each type of control character).  Thus, various
    display problems may result, such as long lines being split in the
    wrong place."

Lines which are too long to fit in the terminal would be word wrapped,
but unfortunately less would get confused about which line it was on,
and text would be drawn on top of other text.  The most noticable case
was shader assembly, which is frequently too wide for an 80 character
terminal, and thus would be drawn on top of the following state packets,
making them completely unreadable.

Using -R instead of -r fixes this problem by only allowing color escape
sequences.  (Notably, Git's implicit pager invocation uses -R.)
Unfortunately, it means our "clear to the end of the line" hack for
extending the blue bar headers won't work anymore.

Word wrapping usually isn't terribly readable, anyway, so we also add
the -S option (chop long lines) to restrict it to the terminal width.
(You can hit the left and right arrow keys to scroll sideways.)

Then, for a new blue bar hack, we can use a printf specifier to pad
the command packet names to be 80 characters long (arbitrarily), which
extends them "far enough" to look good, and doesn't require us to use
ioctls to determine the terminal width.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 src/intel/tools/aubinator.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/intel/tools/aubinator.c b/src/intel/tools/aubinator.c
index a31dcb2..5666fe3 100644
--- a/src/intel/tools/aubinator.c
+++ b/src/intel/tools/aubinator.c
@@ -48,7 +48,6 @@
 #define CSI "\e["
 #define HEADER CSI "37;44m"
 #define NORMAL CSI "0m"
-#define CLEAR_TO_EOL CSI "0K"
 
 /* options */
 
@@ -721,7 +720,7 @@ parse_commands(struct gen_spec *spec, uint32_t *cmds, int size, int engine)
       }
       length = gen_group_get_length(inst, p);
 
-      const char *color, *reset_color = CLEAR_TO_EOL NORMAL;
+      const char *color, *reset_color = NORMAL;
       uint64_t offset;
 
       if (option_full_decode)
@@ -739,7 +738,7 @@ parse_commands(struct gen_spec *spec, uint32_t *cmds, int size, int engine)
       else
          offset = 0;
 
-      printf("%s0x%08lx:  0x%08x:  %s%s\n",
+      printf("%s0x%08lx:  0x%08x:  %-80s%s\n",
              color, offset, p[0],
              gen_group_get_name(inst), reset_color);
 
@@ -1013,7 +1012,7 @@ setup_pager(void)
    if (pid == 0) {
       close(fds[1]);
       dup2(fds[0], 0);
-      execlp("less", "less", "-rFi", NULL);
+      execlp("less", "less", "-FRSi", NULL);
    }
 
    close(fds[0]);
-- 
2.10.0