About
Various testing on conditional events or variables (exit test, variable defaults).
Last Command Return Value
Make sure you have spaces inside the [] otherwise bash will sit the dummy!
Check for Success
if [ $? -eq 0 ]; then echo "Success" else echo "Failure"
Check for Failure
if [ $? -ne 0 ]; then echo "Failure" else echo "Success"
Conditionally Set Variables
Set if not already defined
: ${var=value}
This one is obscure....<TODO> explain!
Set if not defined OR set to the empty string
: ${var:=value}
Copy Selected Files
Recursively Copy Selected Files with Folder Structure
cp --parents `find -name .pydevproject` /target_directory/
Install Packages
Install packages via sudo only if it is not already installed
install_package ()
{
PACKAGE_NAME=$1
dpkg -s ${PACKAGE_NAME} > /dev/null
if [ $? -ne 0 ]; then
sudo apt-get -q -y install ${PACKAGE_NAME} > /dev/null
else
pretty_print " $(padded_message ${PACKAGE_NAME} "found")"
return 0
fi
if [ $? -ne 0 ]; then
pretty_error " $(padded_message ${PACKAGE_NAME} "failed")"
return 1
fi
pretty_warning " $(padded_message ${PACKAGE_NAME} "installed")"
return 0
}
# usage
install_package ansible