Difference between revisions of "Bash"
From Blue-IT.org Wiki
(→Environment) |
|||
| Line 6: | Line 6: | ||
export LC_TYPE="en_US.UTF-8" | export LC_TYPE="en_US.UTF-8" | ||
export LANGUAGE="en_US.UTF-8 | export LANGUAGE="en_US.UTF-8 | ||
| + | |||
| + | |||
| + | == Singleton == | ||
| + | |||
| + | The [http://en.wikipedia.org/wiki/Singleton_pattern singleton] pattern is a very handy one. You can realise it in bash like this: | ||
| + | |||
| + | if ps x | grep -v grep | grep -v $$ | grep $0 | grep -v subl | grep -v vi | ||
| + | then | ||
| + | echo "$0 already running. Exiting" | ||
| + | exit 1 | ||
| + | else | ||
| + | |||
| + | ################################################ | ||
| + | # PUT YOUR CODE HERE | ||
| + | # vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv | ||
| + | |||
| + | ./run_me | ||
| + | |||
| + | # ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | ||
| + | ################################################ | ||
| + | |||
| + | fi | ||
== Grep and Tail == | == Grep and Tail == | ||
Revision as of 08:32, 8 January 2014
Environment
Put this in front of any script to avoid problems when running the script in other languages! The en_US locale should be avaiabel on all systems:
export LC_MESSAGES="en_US.UTF-8" export LC_TYPE="en_US.UTF-8" export LANGUAGE="en_US.UTF-8
Singleton
The singleton pattern is a very handy one. You can realise it in bash like this:
if ps x | grep -v grep | grep -v $$ | grep $0 | grep -v subl | grep -v vi
then
echo "$0 already running. Exiting"
exit 1
else
################################################
# PUT YOUR CODE HERE
# vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
./run_me
# ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
################################################
fi
Grep and Tail
tail -f -n 300 /var/log/syslog | stdbuf -o0 grep PATTERN