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Tutorial12: Shell Scripting - Part 2

10 bytes added, 08:53, 21 March 2021
INVESTIGATION 3: exit AND break STATEMENTS
# Save your editing session and exit the text editor (eg. with vi: press '''ESC''', then type ''':x''' followed by '''ENTER''').<br><br>
# '''Add execute permissions''' for this Bash shell script.<br><br>
# Issue the following command (without arguments):<br><span style="color:blue;font-weight:bold;font-family:courier;">./exit.bash</span><br><br>What did you notice?<br><br>Since there are no arguments, the test within the running shell script returns FALSE,<br>then an '''error message''' with feedback of how to properly issue the shell script with an argument<br>and then '''terminates''' the Bash shell script.<br><br>Notice that the '''$0''' positional parameter displays the '''name''' of the currently running shell script<br>in the USAGE message. This is useful in case you decide to '''change ''' the ''name '' of the shell script at a later time.<br><br>The symbol '''&gt;&amp;2''' redirects '''standard output''' from the USAGE message<br>to '''standard error''' making like a <u>real</u> error message.<br>This "''neat redirection trick''" will NOT be considered for evaluation for this coverage.<br><br>
# Issue the following Linux command:<br><span style="color:blue;font-weight:bold;font-family:courier;">echo $?</span><br><br>What does this '''exit status''' from the previously issued command indicate?<br><br>
# Issue the following command (with an argument):<br><span style="color:blue;font-weight:bold;font-family:courier;">./exit.bash uli101</span><br><br>What did you notice this time?<br><br>
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