Here we are going to talk on Bash programming whch is quite powerful when It comes to automating a process in unix environment. Here we go.
1. Declaring Variable
variable_x= test_val
variable_y=$variable_x
2. Declaring command output in a variable
command= some unix command here
variable_x=`unix_command`
3. Conditional Statement
if
then
// do something
fi
#If Else If syntax goes here
if
then
// do something
else
// do something else
fi
4. Replacing some content or value of a variable into a file
$variable_x > some_file.txt
5. Storing the content of a file in a variable
variable_form_content=$(<disk_file.txt)
6. Conditional check for 0
//check if variable_x is zero
if [ -z "$variable_x is" ]
then
//do something
fi
7. Conditional check for no command output/null
variable_command_output=`command`
if [ -n "$variable_command_output" ]
then
//do something
fi
8. Check for equality
if [ $variable_x=="test_value" ]
9. Creating file at run time
new_file= hello_world_$(date +"%m_%d_%Y_%s").txt
10. Displaying output on console while piping to some other file
command | tee $piped_out_put_file
11. Assigning scanned file output to a variable
output_variable=`cat some_file.txt |grep "scan_some_text"`
12. Running command in a new process
( command &)
13. Do while loop
while (( ++some_variable_count <= limit )) ;do
// do something
done
14. Wait for some time
sleep // in seconds
15. Passing argument to a funtction.
function function_name {
command...
}
function_name "$arg1" "$arg2"