Friday, June 28, 2013

3 days using i3 tiling window manager under Slackware

I have heard about tiling window manager for some time, but lack the initiative to test one.  Recently I finally got fed up with resizing two windows side by side and decided to give titling manager a test.

After some research from the web, I settled on i3 tiling window manager for its simplicity.  With the help from SlackBuilds, I got the window manager installed and run without hassle (I did recompile the cairo with xcb support (from current) and use the latest i3 release version 4.5.1).

It took me a while to get familiar with the key bindings.  Thanks for the good documentation, I got used to it quickly and customized the configuration to suite my own needs.  No longer do I need to fight with the mouse to place the window to gain the last pixel.  Wow, I wish I should try it earlier.  It just simply awesome! Oh, and awesome is another good tiling window manager too ^_^.

I have used various window mangers and DE during the years of using Slackware.  From the beginning, it was fvwm, fvwm2, IceWM, window maker, GNOME, KDE, XFCE, LXDE, blackbox, EDE, E16, E17, fluxbox.  Now I am simply sold to the tiling manager and won't go back to the normal one.

Thursday, June 13, 2013

Problem with wireshark 1.10.0 in Slackware 14

I just tried to compile wireshark 1.10.0 under Slackware64 14.0, using the build script from SBo.

It compiled fine, but running with segmentation fault.  It seems wireshark itself try to use libnl3 but libpcap in Slackwre is using libnl (version 1).  After adding configuration "--with-libnl=1" to force wireshark to use version 1 of libnl, it does not crash anymore.

But it did not use gnutls, it seems the version (3.0.23) in Slackware is too old, it required at least 3.1.10.  Currently, the latest stable version is 3.2.1, but it requires update nettle to 2.7 also.  I ended up update the gnutls lib to 3.1.12 to compile wireshark with tls support.

It seems Slackware-current does not update gnutls library yet, hope next version of Slackware could update the gnutls version to a newer one.

PS. seems nettle 2.7.1/gnutls 3.2.1/wireshark 1.10.0 works fine after I recompiled the 3 packages.

Tuesday, June 11, 2013

git error message '... does not point to a valid object'

I tried to sync my local git repository to the remote server and got some error messages saying certain objects are not valid object: "... does not point to a vlid object".

After searching the net, these two commands solve my problem:

git remote prune origin
git gc --prune=now

After that, re-sync my repository without problem.

Thursday, May 9, 2013

Google Glass?

Google Glass seems grasp quite some attention.  From the limited information gathered, I don't see it an attractive gadget at all.

I am not speaking from technical points of view, like processor power, battery life, user interface, etc. but its usage point of view.

Maybe for some specific venues or activities, it could a good use, but not in general usage.  The display/notification from it disturb one's attention, it may danger your life, especially when you are driving or walking on the street, your attention got diverted and tragic accident would happen.  I could imagine there would be laws to ban usage of Google glass when driving if it could ever reach that kind of massive market.  Maybe Google should add a small radar into it to prevent collision ^_^

I am not sure how much would it affecting one's vision health when switching your eye focus back and forth from the display to background scene.  Would it have any bad effect on how the brain process vision?

Wednesday, December 5, 2012

GNU indent regression with --blank-lines-after-declarations in 2.2.10

The GNU indent program includes in Slackware 14 has a regression bug.

After searching, it seems there is an unofficial release 2.2.11, which could be located from Debian source.  The release fixed the problem.

After downloaded the source from the above URL and also the Debian tar ball (indent_2.2.11.orig.tar.gz was gunziped, renamed to indent-2.2.11.tar then xzed).  Slackware's official build script was downloaded also.  It was modified to compile the newer version and include patches from Debian:


#!/bin/sh

# Copyright 2008, 2009, 2010  Patrick J. Volkerding, Sebeka, MN, USA
# All rights reserved.
#
# Redistribution and use of this script, with or without modification, is
# permitted provided that the following conditions are met:
#
# 1. Redistributions of this script must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
#
#  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
#  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
#  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
#  EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
#  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
#  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
#  OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
#  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
#  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
#  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


VERSION=${VERSION:-2.2.11}
BUILD=${BUILD:-1}

# Automatically determine the architecture we're building on:
if [ -z "$ARCH" ]; then
  case "$( uname -m )" in
    i?86) export ARCH=i486 ;;
    arm*) export ARCH=arm ;;
    # Unless $ARCH is already set, use uname -m for all other archs:
       *) export ARCH=$( uname -m ) ;;
  esac
fi

if [ "$ARCH" = "i486" ]; then
  SLKCFLAGS="-O2 -march=i486 -mtune=i686"
elif [ "$ARCH" = "i686" ]; then
  SLKCFLAGS="-O2 -march=i686 -mtune=i686"
elif [ "$ARCH" = "s390" ]; then
  SLKCFLAGS="-O2"
elif [ "$ARCH" = "x86_64" ]; then
  SLKCFLAGS="-O2 -fPIC"
else
  SLKCFLAGS="-O2"
fi

NUMJOBS=${NUMJOBS:-" -j7 "}

CWD=$(pwd)
TMP=${TMP:-/tmp}
PKG=$TMP/package-indent
rm -rf $PKG
mkdir -p $TMP $PKG

cd $TMP
rm -rf indent-$VERSION
tar xvf $CWD/indent-$VERSION.tar.xz || exit 1
cd indent-$VERSION
chown -R root:root .
find . \
  \( -perm 777 -o -perm 775 -o -perm 711 -o -perm 555 -o -perm 511 \) \
  -exec chmod 755 {} \; -o \
  \( -perm 666 -o -perm 664 -o -perm 600 -o -perm 444 -o -perm 440 -o -perm 400 \) \
  -exec chmod 644 {} \;

# GCC4 fix
#sed -i -e 's#extern FILE \*output#static FILE *output#' src/indent.h || exit 1

#apply patches from Debian 
for file in $CWD/patches/* ; do
    patch -p1 < $file
done

CFLAGS="$SLKCFLAGS" \
CXXFLAGS="$SLKCFLAGS" \
./configure \
  --prefix=/usr \
  --sysconfdir=/etc \
  --localstatedir=/var \
  --mandir=/usr/man \
  --infodir=/usr/info \
  --build=$ARCH-slackware-linux

make $NUMJOBS || make || exit 1
make install DESTDIR=$PKG

# I'm not sure why this man page fails, but...
if find $PKG -type f -size 0c -name indent.1 ; then
  ( cd man
    ./texinfo2man ./indent.1.in ./../doc/indent.texinfo > indent.1
    cat indent.1 > $PKG/usr/man/man1/indent.1
  )
fi

# Strip binaries and libraries:
find $PKG | xargs file | grep -e "executable" -e "shared object" \
  | grep ELF | cut -f 1 -d : | xargs strip --strip-unneeded 2> /dev/null

# Compress man pages:
( cd $PKG/usr/man
  find . -type f -exec gzip -9 {} \;
  for i in $( find . -type l ) ; do
    ln -s $( readlink $i ).gz $i.gz ; rm $i
  done
)

# Compress info pages and remove the package's dir file:
rm -f $PKG/usr/info/dir
gzip -9 $PKG/usr/info/*.info*

# Copy program documentation into the package:
mkdir -p $PKG/usr/doc/indent-$VERSION
cp -a \
  AUTHORS COPYING* NEWS README \
  $PKG/usr/doc/indent-$VERSION
chmod 644 $PKG/usr/doc/indent-$VERSION/*

mkdir -p $PKG/install
cat $CWD/slack-desc > $PKG/install/slack-desc

# Build the package:
cd $PKG
/sbin/makepkg -l y -c n $TMP/indent-$VERSION-$ARCH-$BUILD.txz

As I have installed texlive 2012 in stead of tetex from the stock Slackware, the newer version of texi2html program does not support the -number option anymore, it has changed to two separate options --number-footnotes and --number-sections.

A patched is developed for it to compile with the new texi2html:

--- indent-2.2.11/doc/Makefile.in 2010-01-31 08:25:21.000000000 -0800
+++ indent-2.2.11.new/doc/Makefile.in 2012-12-05 11:40:30.130229271 -0800
@@ -663,14 +663,14 @@
 html-split: @PACKAGE@_toc.html
 
 @PACKAGE@.html: version.texi $(@PACKAGE@_TEXINFOS)
- $(TEXI2HTML) -expandinfo -number -monolithic `if test -f @PACKAGE@.texinfo; then echo @PACKAGE@.texinfo; else echo $(srcdir)/@PACKAGE@.texinfo; fi`
+ $(TEXI2HTML) -expandinfo --number-sections --number-footnotes -monolithic `if test -f @PACKAGE@.texinfo; then echo @PACKAGE@.texinfo; else echo $(srcdir)/@PACKAGE@.texinfo; fi`
 
 @PACKAGE@_toc.html: version.texi $(@PACKAGE@_TEXINFOS)
  case "$(TEXI2HTML)" in \
    *"/missing texi2html") \
-      $(TEXI2HTML) -expand info -number -nomenu -split section `if test -f @PACKAGE@.texinfo; then echo @PACKAGE@.texinfo; else echo $(srcdir)/@PACKAGE@.texinfo; fi` || exit 0 ;; \
+      $(TEXI2HTML) -expand info --number-sections --number-footnotes -nomenu -split section `if test -f @PACKAGE@.texinfo; then echo @PACKAGE@.texinfo; else echo $(srcdir)/@PACKAGE@.texinfo; fi` || exit 0 ;; \
    *) $(RM) @PACKAGE@_*.html ; \
-      $(TEXI2HTML) -expand info -number -nomenu -split section `if test -f @PACKAGE@.texinfo; then echo @PACKAGE@.texinfo; else echo $(srcdir)/@PACKAGE@.texinfo; fi` ;; \
+      $(TEXI2HTML) -expand info --number-sections --number-footnotes -nomenu -split section `if test -f @PACKAGE@.texinfo; then echo @PACKAGE@.texinfo; else echo $(srcdir)/@PACKAGE@.texinfo; fi` ;; \
  esac
 
 install-html-monolithic: @PACKAGE@.html

The compilation went smoothly after applying all the patches and the regression is fixed.

Friday, November 30, 2012

Ref: How to convert from UTC to local time in C?

Reference: How to convert from UTC to local time in C?

I think the following from stackoverflow is the best portable solution if timegm() is not in the system.

#include <stdio.h>
#include <time.h>
#include <assert.h>

time_t my_timegm(struct tm *tm) {
    time_t epoch = 0;
    time_t offset = mktime(gmtime(&epoch));
    time_t utc = mktime(tm);
    return difftime(utc, offset);
}


int main(void) {
    time_t now = time(0);
    struct tm local = *localtime(&now);
    struct tm utc = *gmtime(&now);
    time_t t1 = mktime(&local);
    time_t t2 = my_timegm(&utc);
    assert(t1 == t2);
    printf("t =%lu\nt1=%lu\nt2=%lu\n",now,t1,t2);
    return 0;
}

Thursday, November 22, 2012

Slackware 14, I still got xxgdb: all ptys in use

In Slackware64 14, I still got the error message when running xxgdb:

xxgdb: all ptys in use

It seems even with the patch of xxgdb-1.12-debian-pty.patch.xz in the stock build scripts, it does not work in Slackware.

I developed a separate patch which use the posix calls.  With the patch and xxgdb-1.12-debian-pty.patch.xz removed, I got a working xxgdb.

The patch could be downloaded here: xxgdb-pty.patch.xz.