Red Hat Bugzilla – Bug 74985
cluttered man pages
Last modified: 2007-04-18 12:47:03 EDT
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Description of problem:
When I went from Red Hat release 7.2 to 7.3, my man pages
started coming up ugly, with "cooked" escape sequences in
them (the escape sequence was being printed as "ESC...").
I took a while, but I think I figured out what's going on.
Apparently, in the transition from 7.2 to 7.3, the way
that bold and underlined strings are formatted in the
man page was changed. In 7.2, a character "X" was made
bold with "X^hX", and underlined with "_^hX". In 7.3,
whole strings are made bold/UL by surrounding them with
The pager less has some built-in smarts for backspace handling,
by default taking a "X^hX" or a "_^hX" in the
input, and converting it in the output to the proper
escape sequence to make it bold or underlined. This is
true regardless of whether or not any of less's "raw"
options are used.
However, if the bold/underline escape sequence appears
in the input, less does not do anything special with it.
If a raw option is specified, escape characters get passed
through untouched. If not, escape characters get converted
to the string "ESC".
I had in my environment "PAGER=less". This is a leftover from
the days when I was working on a UNIX that used more (or pg -- ich!)
as the default pager.
Since I did not specify any options to less, I was getting the
default behavior of cooked escape sequences, resulting in ugly
Once I figured out the problem, the workaround was obvious.
Get rid of the PAGER setting in my environment. Since man's
default pager now does what I want (less, with the raw option), I
don't need to specify my own.
This bug can probably be resolved as a "no change". I mostly
like the change. If you're going to have formatting characters
in the page, having the escapes instead of the backspaces
has some obvious advnatages:
- you get your bolds/underlines even if you are not piping to a
pager smart enough to know what to do with the backspaces -- even
if the output is going direct to the terminal (assuming a smart
enough terminal, which is *almost* always a safe assumption).
- greps for strings that are bolded/ULed work
The only thing I don't like is the trouble it caused me for
I'm mostly entering this bug as a public service to anyone else
out there who might run into this problem and go looking in
bugzilla for a solution (like I did).
Version-Release number of selected component (if applicable):
Steps to Reproduce:
PAGER=less man ls
works with a standard 8.0 config with the standard pager. thanks for the tip though