I won't even try to admit I understood all that... I'm just 1-1/2 years old
in Linux time :)
My reason for killing the export of LESSOPEN was because "less" didn't work,
and I was working on something where I needed it to work... right then. Once
I got it working, I never pursued it further.
Don't know if this will help you track it down, but here's some thing's I've
noticed.
1) "less" works fine in the console, both as a normal user and root.
2) "less" does not work from the terminal window in KDE as a normal user. It
does work if you're root, or if you "su -" to root. Trying to "less a file as
a normal user in a KDE terminal window yields:
ESC[361ESC>
filename 1-1/1 (END)
Replace filename with whatever you're "less"ing.
FWIW, this is a brand new install of 7.2, (8.0 refused to boot on my system).
-Al
On Friday 22 June 2001 21:14, Pierre Fortin wrote:
> Al Andersen wrote:
> > I had the same problem with my 7.2 system. The way I resolved it was to
> > edit /etc/profile and comment out:
> >
> > #if [ -x /usr/bin/lesspipe.sh ];then
> > # export LESSOPEN="|/usr/bin/lesspipe.sh %s"
> > #fi
> >
> > Your mileage may vary :)
>
> MMDV... unfortunately, this kills the useful stuff within lesspipe.sh,
> like automatic handling of different file types.
>
> More digging... the problem is the way 'less' pipes <filename> to
> $LESSOPEN when the latter starts with "|" (doh! :^)...
>
> Tried a lot of different things; hopefully I got the results straight...
>
> export LESSOPEN="| /bin/sh --norc /usr/bin/lesspipe.sh %s"
> ^^^^^^^^^^^^^^
> starts a shell which for some reason ignores "--norc" whether specified
> here or on the #!/bin/sh line within lesspipe.sh...
>
>
> Without the pipe symbol, less invokes "$SHELL -c $LESSOPEN" which makes it
> impossible to use --norc here.
>
>
> export SHELL=/bin/csh
> Changing the shell avoids .bashrc; but lesspipe.sh still invokes /bin/sh.
> To change this to '#!/bin/csh' requires rewriting lesspipe.sh... Adding
> --norc to the shebang line does nothing. Not sure if .cshrc would have the
> same problem...
>
>
> export LESSOPEN="| /bin/cat %s"
> This still invokes .bashrc...
>
>
> export LESSOPEN="/bin/sh --norc < /usr/bin/lesspipe.sh %s"
> export LESSOPEN="|/bin/sh < /usr/bin/lesspipe.sh %s"
> export LESSOPEN="|/bin/sh --norc < /usr/bin/lesspipe.sh %s"
> These kinda work; but on "q[uit]", "less foo.html" gives:
> foo.html: line 1: syntax error near unexpected token `<html>'
> foo.html: line 1: `<html>'
> starts a shell which for some reason will not accept "--norc" either on the
> #!/bin/sh line, or within LESSOPEN...
>
>
> export LESSOPEN="/bin/sh < /usr/bin/lesspipe.sh %s"
> This variation also kinda works; but gives:
> bin/sh: Command not found.
>
>
> The bottom line is that anything in .bashrc will execute because running
> "less" results in implicitly doing a "source .bashrc", not to mention that
> anything ..bashrc sends to STDOUT is injected into the pipe... On the
> whole, this seems poorly thought out... though my C skills are quite rusty
> from lack of use and old age... :}
>
> However, creating lesspipe.py and using:
> export LESSOPEN="| /usr/bin/lesspipe.py %s"
> avoids the shell timebombs... here's a Python version (based on LM7.2;
> 8.0's lesspipe.sh is much different):
>
> -----------------------------------
> #!/usr/bin/env python
>
> import os, sys, re
>
> FILE = sys.argv[1]
>
> TYPE = os.popen("file -L %s | cut -d' ' -f2-" % FILE ).read()
>
> if re.match('gzip', TYPE): CMD='gzip -d -c -q'
> elif re.match('compress\'d\ data', TYPE): CMD='uncompress -c'
> elif re.match('GNU\ tar', TYPE): CMD='tar -tvf'
> elif re.match('Zip', TYPE): CMD='unzip -c -qq'
> elif re.match('Zoo', TYPE): CMD='zoo xqp'
> elif re.match('ARC', TYPE): CMD='arc pn'
> elif re.match('LHa', TYPE): CMD='lha p'
> elif re.match('RAR', TYPE): CMD='unrar p'
> elif re.match('RPM', TYPE): CMD='rpm -qpil'
> #elif re.match('ARJ', TYPE): unset CMD
> elif re.match('ELF', TYPE): CMD='strings'
> elif re.match('Linux/i386', TYPE): CMD='strings'
> elif re.match('MS-DOS\ executable', TYPE): CMD='strings'
> elif re.match('MS-Windows', TYPE): CMD='strings'
> elif re.match('Win95\ executable', TYPE): CMD='strings'
> elif re.match('bzip2\ compressed', TYPE): CMD='bunzip2 -d -c'
> elif re.match('bzip\ compressed', TYPE): CMD='bunzip -d -c'
> elif re.search(".bz$", sys.argv[1]): CMD='bunzip -d -c'
> elif re.search(".bz2$", sys.argv[1]): CMD='bunzip2 -d -c'
> else: CMD=None
>
> if CMD:
> print os.popen("%s %s 2> /dev/null" % ( CMD, FILE )).read()
> -----------------------------------
>
> Note: no logic was corrected in this simple (7.2) re-write...
>
> HTH,
> Pierre
>
> > -Al
> >
> > On Friday 22 June 2001 13:51, Pierre Fortin wrote:
> > > Hi,
> > >
> > > Before I go digging into the sources, does anyone know the logic behind
> > > "less" being impacted by the contents of .bashrc...?
> > >
> > > If I add 'echo "foobar"' to my .bashrc, any attempt to "less <file>"
> > > gives only "foobar" as output instead of the expected contents of
> > > <file>.
> > >
> > > The env. vars are:
> > > $ for e in ${!LESS*}; do echo $e ${!e};done
> > > LESS -MM
> > > LESSKEY /etc/.less #doesn't exist
> > > LESSOPEN |/usr/bin/lesspipe.sh %s #nothing weird here
> > >
> > > I've strace'd it and see this line:
> > > pipe([5, 6]) = 0
> > > (the numbers are not always 5 & 6) which is probably from the LESSOPEN
> > > pipe...
> > >
> > > I don't see less opening .bashrc or invoking it; but less somehow gets
> > > output from .bashrc... What I can't determine yet is whether this
> > > "output" is from ..bashrc executing anew when less is run (most likely
> > > -- see below), or from a stale buffer somewhere... I just can't
> > > imagine a scenario where less needs to either access .bashrc or get
> > > data from a non-user-specified pipe... could this be a potential
> > > security hole...?
> > >
> > > The problem is even more confusing if I add some code to .bashrc; it
> > > gets executed when I invoke less, instead of displaying the requested
> > > file... this would seem to indicate .bashrc is executed when less is
> > > invoked...
> > >
> > > This happens on both my LM7.2 machines; but not on the 8.0 one, though
> > > the latter has the same env. vars and the same pipe in strace output...
> > > but, the default .bashrc is different...
> > >
> > > Puzzling.
> > >
> > > Pierre
