My Linux Notes

2018-07-31

My Linux Notes

Installing Trac 12 on Centos 5.5 – requires Python 2.6

SSH tunelling

Mapovani vzdaleneho portu na vzdalenem stroji na lokalni port:

ssh -L localPort:TargetPC:RemotePort PCsSSHaccountem

Zpristupneni lokalniho portu na zvoleny port vzdaleny:

ssh -R VzdalenyPort:LokalniPC:LokalniPort PCsSSHaccountem

Bash string operations

${parameter:-word}   # Provide a default if parameter is unset or null.

${variable%pattern}   # Trim the shortest match from the end.
${variable##pattern}  # Trim the longest match from the beginning.
${variable%%pattern}  # Trim the longest match from the end.
${variable#pattern}   # Trim the shortest match from the beginning.

Current script

scriptPath="$(cd "${0%/*}" 2>/dev/null; echo "$PWD"/"${0##*/}")"
scriptDir=`dirname "$scriptPath"`

JAVA=/mnt/jqa/jdk1.6.0_18-x86_64/bin/java

$JAVA -cp $scriptDir/JiraBot-1.1.04.jar:`ls $scriptDir/lib/*.jar | awk '{ORS=":";print}'` org.jboss.jirabot.Main

Colorful prompt

PS1='${debian_chroot:+($debian_chroot)}\e[1;31m\u@\h:\w\$\e[m '

32 green
35 magenta
40 white
31 red
33 yellow
34 blue 
# resolve links - $0 may be a softlink
PRG="$0"

while [ -h "$PRG" ] ; do
  ls=`ls -ld "$PRG"`
  link=`expr "$ls" : '.*-> \(.*\)$'`
  if expr "$link" : '/.*' > /dev/null; then
    PRG="$link"
  else
    PRG=`dirname "$PRG"`/"$link"
  fi
done

(from Tomcat's star­tup.sh)

##  Resolve a softlink.
function resolve(){

  PRG="$1"

  if [ "" == "$1" ] ; then
    return ""
  fi

  if [ ! -x "$PRG" ] ; then
    PRGW=`which "$PRG"`
    if [ ! -x "$PRGW" ] ; then
      RET=""
      return -1
    fi
  fi


  while [ -h "$PRG" ] ; do
    ls=`ls -ld "$PRG"`
    link=`expr "$ls" : '.*-> \(.*\)$'`
    if expr "$link" : '/.*' > /dev/null; then
      PRG="$link"
    else
      PRG=`dirname "$PRG"`/"$link"
    fi
  done

  RET=$PRG
  return 0
}

##  If called instead of sourced
if [ "resolve" == "${0: -7}" ] ; then
  if [ "" == "$1" ] ; then
    echo "Usage:  resolve <softlink>";
    exit
  fi

  resolve $1
  if [ "" == "$RET" ] ; then
    echo "$PRG not found."
  else
    echo $RET;
  fi
fi

Snippets

cvs -d:gserver:cvs.devel.redhat.com:/cvs/dist checkout httpd
tcpdump -w snap -s2000 -i eth0
keytool -list -keystore /qa/home/ozizka/opt/jdk1.6.0_18/jre/lib/security/cacerts
keytool -import -alias support.stage.redhat.com -keystore /qa/home/ozizka/opt/jdk1.6.0_18/jre/lib/security/cacerts -file stage-cert.pem
# Debian root
PS1='\[\e[1m\]\[\e[31m\]\u@\h \[\e[0m\]\[\e[32m\][\[\e[33m\]\t\[\e[32m\]]\[\e[33m\]\[\e[1m\] \w\[\e[32m\]\[\e[0m\] \$ '

# Debian:
export PS1='${debian_chroot:+($debian_chroot)}\e[1;34m\u@\h:\e[1;33m\w\e[1;34m\$\e[m '

# Generic:
export PS1='\e[1;34m\u@\h:\e[1;33m\w\e[1;34m\$\e[m '

# Plain:
export PS1='\u@\h:\w\$ '

export PATH=$JAVA_HOME/bin:$PATH
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