Misc unix commands

chmod only dirs, using find
find /dir/to/chmod/all/dirs -type d -exec chmod a+x {} \;

Move all files after a certain date (Yesterday) , using find
find /dir/ -mtime -1 -exec mv {} ./temp \;

List only directories

ls -l | grep ^d

Find last created entity (file or directory)

ls -t ${CIDIR}| head -n 1

Find last created directory (note must use long ls results, therefore we need to parse 8th elment)

ls -tl | grep ^d | head -n 1 | awk '{print $8}'

grep multiple log files in different locations. (Join multiple lines into one line)

grep EXCEPTION `ls -t /var/log/bea/logs/MWOSBDomain/servers/MWOSB1?/customaudit/LogFile1?.log.* | head -n 3 |  tr '\n' ' '`

e.g. this will grep log files in differnt locations from yesterday (based on naming convention LogFile12.log = current log file. LogFile12.log. is rolled over log file. Assuming log files roll over every night).

Top 3 files are taken from ls command (in this case I know there are 3 log directories, so top 3 files are all yesterdays file in each directory)

List output is then 'translated', converting each line break into a space, so feed into grep command.

Dirname

Discovers the dir where the current running script is running;

Useful if writing bash scripts and you want to know where the current file is (for example if loading other companion scripts)

DIR="$( cd "$( dirname "$0" )" && pwd )"

e.g

#!/bin/bash

export DIRNAME=$(cd `dirname $0` && pwd)

source ${DIRNAME}/common.sh

#echo $JAVA_HOME/bin/java -cp $CLASSPATH ie.bge.middleware.envstatus.app.SetSystemStatus $@

$JAVA_HOME/bin/java -cp $CLASSPATH ie.bge.middleware.envstatus.app.SetSystemStatus $@

N.B. script must be executable. Therefore chmod +x

Parse log file with awk

awk normally splits lines based on whitespace characters. This can be forced however using the -F switch and passing a regex.

e.g. the following splits on semi-colon, and prints the 3rd and 6th fields.

awk -F ";" '{print $3 " " $6 }'

this example splits on commas, within quotes e.g. "value1", "value2", ..

awk -F "\"*,\"*" '{print $3}' file.csv

Identify unix version

uname -r

cat /etc/*-release

cat /etc/issue

rpm -qa --queryformat "%{NAME}-%{VERSION}-%{RELEASE}.%{ARCH}\n"|grep release|sort

Misc Tips

Whitepace gothcas when writing bash scripts.

Bash IF statment requires whitespace.

DIRNAME=mydir

if [ -d $DIRNAME ]; then

echo $DIRNAME exists

else

echo $DIRNAME does not exist

fi

1/ There must be NO whitespace in the set command (DIRNAME=mydir, ..e.g. the following won't work DIRNAME = mydir). Otherwise bash misinterprets the set operation as a command (called DIRNAME here).

2/ The whitespace between the IF statement and the [..] is required. e.g. (if [-d $DIRNAME]; then will cause an error)

Script to copy latest build folder to other location

#!/bin/bash

# Exit on Error

set -e

DIR=/usr/local/apache2/htdocs/Repository

CIDIR=/opt/continuous_integration/build_archive/

echo $#

if [ $# -ne 1 ]; then

echo Usage: PublishBuild.sh VER. Must supply version number.

exit 1

fi

VER=$1

if [ ! -d ${DIR}/$VER ]; then

mkdir ${DIR}/$VER

fi

if [ ! -d ${DIR}/${VER}/osb ]; then

mkdir ${DIR}/$VER/osb

fi

CIB=`ls -t ${CIDIR}| head -n 1`

echo cp -R ${CIDIR}/${CIB}/* ${DIR}/${VER}/osb

cp -R ${CIDIR}/${CIB}/* ${DIR}/${VER}/osb

echo Copied ${CIB} to ${VER}

exit 0