Commands by keymon

Will check if the given module is installed in the @INC. It will print the path and return 0 if found, or 1 otherwise.

Based on script from SharpyWarpy in http://www.linuxquestions.org/questions/linux-general-1/how-to-list-all-installed-perl-modules-216603/

Got the idea from there http://fixunix.com/questions/15902-bash-checking-if-env-var-set.html

This works in multiple unixes, not only linux, for different paths.

On solaris, if you do not have which, you can use:

ksh whence -p anypath/a_command.sh | sed "s|^./|$(pwd)|" ksh whence -p

Will print the host associated with the current stdin.

This is useful to set the DOIT_SERVER for the doit remote execution agent ( http://www.chiark.greenend.org.uk/~sgtatham/doit/ )

export DOIT_HOST=$(who -m | sed 's/.*(\(.*\)).*/\1/')

Note that SSH_CLIENT variable can be lost if you use su or sudo (if set to reset vars)

It will return the absolute location of the called a script. If is in $PATH, it will search it using which.

You can combine this function with this other one: http://www.commandlinefu.com/commands/view/9252/readlink-equivalent-using-shell-commands-and-following-all-links, to get a way to know where is the real location of a called script:

This is a equivalent to the GNU ' readlink' tool, but it supports following all the links, even in different directories.

An interesting alternative is this one, that gets the path of the destination file

If you make a mess (like I did) and you removed all the executable permissions of a directory (or you set executable permissions to everything) this can help.

It supports spaces and other special characters in the file paths, but it will work only in bash, GNU find and GNU egrep.

You can complement it with these two commands:

1. add executable permission to directories:

2. and remove to files:

Or, in the same loop:

Ideas stolen from Greg's wiki: http://mywiki.wooledge.org/BashFAQ/020

Using gentoo prefix portage I got in a situation where some packages did not contain the needed RPATH variable. This command helped me to find out which ones I should recompile

It can work for message queue, semaphore set or shared memory just changing the parameter.

AIX lssec does not print the password attribute by policy

# lssec -c -f /etc/security/passwd -s an_user -a password

3004-697 Attribute "password" is not valid.

To get the password, you have to parse the /etc/security/passwd.

You can reuse this password using chpasswd:

echo "otheruser:D9oKC1v3VUt/I" | chpasswd -c -e -R compat

Based on the execute with timeout command in this site.

A more complex script:

#!/bin/sh

# This script will check the avaliability of a list of NFS mount point,

# forcing a remount of those that do not respond in 5 seconds.

#

# It basically does this:

# NFSPATH=/mountpoint TIMEOUT=5; perl -e "alarm $TIMEOUT; exec @ARGV" "test -d $NFSPATH" || (umount -fl $NFSPATH; mount $NFSPATH)

#

TIMEOUT=5

SCRIPT_NAME=$(basename $0)

for i in $@; do

echo "Checking $i..."

if ! perl -e "alarm $TIMEOUT; exec @ARGV" "test -d $i" > /dev/null 2>&1; then

echo "$SCRIPT_NAME: $i is failing with retcode $?."1>&2

echo "$SCRIPT_NAME: Submmiting umount -fl $i" 1>&2

umount -fl $i;

echo "$SCRIPT_NAME: Submmiting mount $i" 1>&2

mount $i;

fi

done

Based on the execute with timeout command in this site.

A more complex script:

#!/bin/sh

# This script will check the avaliability of a list of NFS mount point,

# forcing a remount of those that do not respond in 5 seconds.

#

# It basically does this:

# NFSPATH=/mountpoint TIMEOUT=5; perl -e "alarm $TIMEOUT; exec @ARGV" "test -d $NFSPATH" || (umount -fl $NFSPATH; mount $NFSPATH)

#

TIMEOUT=5

SCRIPT_NAME=$(basename $0)

for i in $@; do

echo "Checking $i..."

if ! perl -e "alarm $TIMEOUT; exec @ARGV" "test -d $i" > /dev/null 2>&1; then

echo "$SCRIPT_NAME: $i is failing with retcode $?."1>&2

echo "$SCRIPT_NAME: Submmiting umount -fl $i" 1>&2

umount -fl $i;

echo "$SCRIPT_NAME: Submmiting mount $i" 1>&2

mount $i;

fi

done

I like much more the perl solution, but without using perl. It launches a backgroup process that will kill the command if it lasts too much.

A bigger function:

check_with_timeout() {

[ "$DEBUG" ] && set -x

COMMAND=$1

TIMEOUT=$2

RET=0

# Launch command in backgroup

[ ! "$DEBUG" ] && exec 6>&2 # Link file descriptor #6 with stderr.

[ ! "$DEBUG" ] && exec 2> /dev/null # Send stderr to null (avoid the Terminated messages)

$COMMAND 2>&1 >/dev/null &

COMMAND_PID=$!

[ "$DEBUG" ] && echo "Background command pid $COMMAND_PID, parent pid $$"

# Timer that will kill the command if timesout

sleep $TIMEOUT && ps -p $COMMAND_PID -o pid,ppid |grep $$ | awk '{print $1}' | xargs kill &

KILLER_PID=$!

[ "$DEBUG" ] && echo "Killer command pid $KILLER_PID, parent pid $$"

wait $COMMAND_PID

RET=$?

# Kill the killer timer

[ "$DEBUG" ] && ps -e -o pid,ppid |grep $KILLER_PID | awk '{print $1}' | xargs echo "Killing processes: "

ps -e -o pid,ppid |grep -v PID | grep $KILLER_PID | awk '{print $1}' | xargs kill

wait

sleep 1

[ ! "$DEBUG" ] && exec 2>&6 6>&- # Restore stderr and close file descriptor #6.

return $RET

}

It will parse the unique_id stanza in ODM database to get the DMX id.

It will change the reserve_lock attribute to all AIX EMC disk attached.