[1] Print the initial environment of a process

strings /proc//environ

This file contains the environment variables that were passed to the executable when it was started via the execve system call.

[2] Shell: Passing a string with spaces to a function

Quote the argument during the call and quote the positional parameter inside the function body.

Function definition: Use double quotes around the positional parameter to prevent the shell from performing word splitting on the value. Use single quotes for literal strings when you don't want any variable expansion -- for example, the string contains a $.

Alternative: Escape individual spaces with a backslash if the preference is to not use quotes.

Function call: Wrap the string or variable in double quotes.

some_func() {
    echo "First argument: $1"
}

arg="Grand Canyon"
some_func "$arg"
some_func Kings\ Canyon
some_func 'Cost: $100'

[3] bash: Calculate the elapsed time

One simple way is to rely on the internal variable, $SECONDS, that tracks the number of seconds elapsed since the shell was started.

It automatically updates every second to reflect total elapsed time. However, you can reset it to zero or any other integer at any point to start a new timer. Subsequent references will return the time elapsed since that assignment.

SECONDS=0
# == perform task ==
echo "Elapsed time of task: $SECONDS seconds"

Labels: Linux Unix Shell

Posted by: Giri Mandalika.    # 11:02 PM Tweet