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

[Gandikota, Sirisha]

>-----Original Message-----
>From: mesa-dev [mailto:mesa-dev-bounces at lists.freedesktop.org] On Behalf Of
>Kenneth Graunke
>Sent: Monday, October 03, 2016 5:59 PM
>To: mesa-dev at lists.freedesktop.org
>Cc: Kenneth Graunke <kenneth at whitecape.org>
>Subject: [Mesa-dev] [PATCH] aubinator: Use less -RS instead of -r for the implicit
>pager.
>
>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
>
[SG]  Works for me
Reviewed-by: Sirisha Gandikota <sirisha.gandikota at intel.com>
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