Bourne scripting How do you do cleanup in a robust way, like to remove temporary when script is finished? What is difference between "sourcing" and "executing" a shell script? You write a shell script that sets an env. variable. A: How can a shell script that calls that shell script get the variable value? B: How can a shell script invoked by that shell script get the variable value? What is the setting to prohibit references to undeclared shell variables? How do you loop through precisely each invocation argument precisely, meaning preserving multiple words, white space, etc.? Use case: Our script just invoked a program in the background. What is a simple and reliable way to check stdout from that program for a certain string, every second until the program finishes? [If not answered by previous answer:] Assuming that you know the desired pid, what is the most reliable way to check whether the process is still running? Using only shell built-in feature, how do I capture just the filename suffix from a file name or path? In a case statement you have "case x* in..." and the directory contains file x123, would the string "x*" or "x123" be tested? In a case statement you have match pattern of "x*" and the directory contains file x123, would the test be for "x*" or against "x123"? How do you efficiently test for the existence of a filesystem node? How do you efficiently test if a filesystem node is a symbolic link? What is difference between aliases and functions? Can you use aliases in functions, and if so, how? What is difference between exit and return statements? You write a function that makes a transformed variant of the input string. A: How does your function access the input string? B: How does your function return the newly generated string? What is a direct way to echo a fixed message if an invoked foreground program exits with failure status? How append to an array variable? Perl scripting How do I do a regular expression match that spans 3 lines? Difference between use and require statements Syntax to define a function CLI option to execute main script body on e for each input file line CLI option to give the perl code inline in the CLI How to read an env variable If you set an env variable, would it affect `` commands, system commands, or the calling shell? BSA Scripting Difference between XO command Remote Execution and Central Execution What do grammar files do?