Linux Basic Part13 CAT LESS MORE HEAD TAIL PIPE WC TEE

30 12 2021
cat -- read file or display file content

cat /etc/passwd

less /etc/passwd

more /etc/passwd

head /etc/passwd - read 1st 10 lines by default
head -5 /etc/passwd - display 1st 5 lines
head -15 /etc/passwd - display 1st 15 lines
head -1 /etc/passwd -display 1st line

tail /etc/passwd - display last 10 lines by default
tail -5 /etc/passwd - display last 5 lines
tail -15 /etc/passwd - display last 15 lines
tail -1 /etc/passwd - display last 1 line

wc /etc/passwd
45 93 2415 /etc/passwd

45 - lines
93 - words
2415 - char or no of bits

wc /etc/group
73 73 997 /etc/group

wc -l /etc/passwd -l no. of line
45 /etc/passwd
wc -w /etc/passwd -w no. of words
93 /etc/passwd
wc -c /etc/passwd -c no. of char
2415 /etc/passwd

du - size on disk

du -h
du -b
du -k

Bash:

cmd option argument

date
Thu Dec 30 11:45:01 IST 2021
wc
^C
date | wc
1 6 29

head -3 /etc/passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
head -3 /etc/passwd | wc -l
3

ls -l
ls | wc -l
ls /
ls / | wc -l

cat /etc/passwd | head
cat /etc/passwd | head -2


head -5 /etc/passwd | tee p5
cat p5

head -30 /etc/passwd

head -30 /etc/passwd | tail -1
head -23 /etc/passwd

head -23 /etc/passwd | tail -3
sed -n "30p" /etc/passwd
sed -n "21p" /etc/passwd

date | tee df1
cat df1
ls
cal

cal | tee df1
cat df1
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