A shell script to automate file tasks

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. What is a shell script?

A A text file of commands that run in order each time the script is run

B A program that can only run once and then deletes itself

2. Which script line copies report.txt into the backup folder?

A mv report.txt backup/

B cp report.txt backup/

3. A backup script must keep the original file where it is. Which command should it use?

A cp

B mv

4. Which line stores a folder name in a variable in a shell script?

A dest = backup

B dest=backup

5. Which line uses the variable dest to copy a file?

A cp data.txt $dest

B cp data.txt dest

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1cp report.txt backup/		Afor f in *.txt; do cp "$f" backup/; done
2chmod +x backup.sh		Bcp notes.txt backup/ mv draft.txt archive/
3A script runs its commands in order, so a script can copy a file and then move another file		CThe script has no execute permission, so ./backup.sh fails with a permission denied error. Run chmod +x backup.sh first.
4A loop in a script repeats the same command for every file that matches a pattern		DCopies report.txt into the backup folder when this line of the script runs
5folder = backup cp a.txt $folder/		ESpaces around the = in a variable assignment. The shell treats folder as a command, so the variable is never set. It should be folder=backup.
6cp a.txt backup/ ./backup.sh		FMakes the script file executable so it can be run as a program

Definitions

shell script

Fill in the Blanks

Complete each line of code by filling in the missing parts.

#!/bin/bash __ notes.txt backup/notes.txt

#!/bin/bash __ report.txt archive/report.txt

DEST=backup cp notes.txt "$____/notes.txt"

for f in *.txt; do cp "$f" backup/ ____

chmod __ backup.sh ./backup.sh

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A #!/bin/bash

B !#/bin/bash

C echo "Backup done"

Question 2

A #!/bin/bash

B SRC=/home/sam/docs

C DEST=/home/sam/backup

D cp SRC/*.txt DEST

Question 3

A NAME = report.txt

B cp $NAME backup/

C echo Copied $NAME

Question 4

A #!/bin/bash

B for f in *.txt; then

C cp $f backup/

D done

Question 5

A #!/bin/bash

B mv archive/ old.txt

C echo Moved old.txt

Answer Key

A shell script to automate file tasks

Section A: Quick Questions

A — A text file of commands that run in order each time the script is run

B — cp report.txt backup/

A — cp

B — dest=backup

A — cp data.txt $dest

Section B: Match the Pairs

cp report.txt backup/ → Copies report.txt into the backup folder when this line of the script runs

chmod +x backup.sh → Makes the script file executable so it can be run as a program

A script runs its commands in order, so a script can copy a file and then move another file → cp notes.txt backup/ mv draft.txt archive/

A loop in a script repeats the same command for every file that matches a pattern → for f in *.txt; do cp "$f" backup/; done

folder = backup cp a.txt $folder/ → Spaces around the = in a variable assignment. The shell treats folder as a command, so the variable is never set. It should be folder=backup.

cp a.txt backup/ ./backup.sh → The script has no execute permission, so ./backup.sh fails with a permission denied error. Run chmod +x backup.sh first.

Section C: Definitions

shell script — A text file of shell commands, such as cp, mv or rm, that run in order each time the script is run, so file tasks like backups can be automated.

Section D: Fill in the Blanks

#!/bin/bash
cp notes.txt backup/notes.txt

#!/bin/bash
mv report.txt archive/report.txt

DEST=backup
cp notes.txt "$DEST/notes.txt"

for f in *.txt; do
  cp "$f" backup/
done

chmod +x backup.sh
./backup.sh

Section E: Spot the Error

B — The first line of a shell script must be the shebang #!/bin/bash, with # first and then !. Written as !#, the system cannot tell which shell should run the script.

D — A variable's value is read by putting $ in front of its name. Without the $, cp looks for a folder literally named SRC. It should be cp $SRC/*.txt $DEST.

A — Shell variable assignments must not have spaces around the = sign. With spaces, the shell treats NAME as a command. It should be NAME=report.txt.

B — A shell for loop opens its body with the keyword do, not then. (then belongs to if statements.) It should be for f in *.txt; do.

B — mv takes the source first and the destination second. The arguments are reversed here. It should be mv old.txt archive/.