CLOs - Working With Files

Question 1

What are basic commands for viewing files and what do they do?

Answer 1

cat - viewing files that are not very long, no scroll-back provided
tac - viewing a file backwards, starting with last line
less - viewing larger files, paging program, lets search and navigate within file, scroll-back, space for next page, -N for line numbers
tail - print last 10 lines of file by default, with -n 15 or just -15 changes it to the 15 last lines
head - opposite of tail

Question 2

what does command do?
wc

Answer 2

Word count gives information about word count, line count etc of file

Question 3

What does this command do?
cat -n

Answer 3

Shows file with line numbers

Question 4

What does this command do?
touch file

Answer 4

• update the access, change and modify times of files
• by default resets files timestampt to match current time
• can also be used to create empty files

Question 5

How can you create new directories?

Answer 5

mkdir sampdir -> creates sample directory named sampdir under current directory

mkdir /usr/sampdir -> creates sample directory under /usr

Question 6

How do you remove an empty directory? Or a directory and all of its contents? How can you do it interactively?

Answer 6

rmdir -> empty directory

rm -rf -> recursive

rm -i -> interactively before every removal

Question 7

What does this command do?
mv

Answer 7

• simply rename a file
• move a file to another location, while possibly changing its name at the same time