Linux Common Commands-view text/cat,tac,more,less,head,tail

Cat: Connect and display files

NAME
cat-concatenate files and print on the standard output

[Email protected] ~]# cat/etc/issue
Red Hat Enterprise Server Release 6.6 (Santiago)
\m

[Email protected] ~]# Cat/etc/fstab

#
#/etc/fstab
# Created by Anaconda on Sun June 21 02:15:00 2015
#
# Accessible filesystems, by reference, is maintained under '/dev/disk '
# See mans Pages Fstab (5), Findfs (8), mount (8) and/or Blkid (8) for more info
#
UUID=57D85756-7680-4C7C-9125-6AD67DAE2C45/EXT4 Defaults 1 1
Uuid=2622a4b4-ddc9-47a3-aa2b-f06bc9bec085/boot EXT4 Defaults 1 2
uuid=33d94759-fa01-4c4f-b4ac-bf3a1fe5e84f swap swap defaults 0 0
TMPFS/DEV/SHM TMPFS Defaults 0 0
Devpts/dev/pts devpts gid=5,mode=620 0 0
Sysfs/sys Sysfs Defaults 0 0
PROC/PROC proc Defaults 0 0
[Email protected] ~]# Cat/etc/issue/etc/fstab
Red Hat Enterprise Server Release 6.6 (Santiago)
\m

#
#/etc/fstab
# Created by Anaconda on Sun June 21 02:15:00 2015
#
# Accessible filesystems, by reference, is maintained under '/dev/disk '
# See mans Pages Fstab (5), Findfs (8), mount (8) and/or Blkid (8) for more info
#
UUID=57D85756-7680-4C7C-9125-6AD67DAE2C45/EXT4 Defaults 1 1
Uuid=2622a4b4-ddc9-47a3-aa2b-f06bc9bec085/boot EXT4 Defaults 1 2
uuid=33d94759-fa01-4c4f-b4ac-bf3a1fe5e84f swap swap defaults 0 0
TMPFS/DEV/SHM TMPFS Defaults 0 0
Devpts/dev/pts devpts gid=5,mode=620 0 0
Sysfs/sys Sysfs Defaults 0 0
PROC/PROC proc Defaults 0 0
[Email protected] ~]#

-N,--number (show line number)
Number all output lines

[Email protected] ~]# cat-n/etc/issue
1 Red Hat Enterprise Server Release 6.6 (Santiago)
2 \m
3

-E,--show-ends (display end symbol $,windows Terminator is $+ carriage return)
Display $ at end of each line

[Email protected] ~]# cat-e/etc/issue
Red Hat Enterprise Server Release 6.6 (Santiago) $
\m$
$

TAC: Flashback display text

NAME
Tac-concatenate and print files in reverse

[Email protected] ~]# cat/etc/issue
Red Hat Enterprise Server Release 6.6 (Santiago)
\m

[Email protected] ~]# tac/etc/issue

\m
Red Hat Enterprise Server Release 6.6 (Santiago)

More, Less: Split screen view

More support to turn back the screen, turn to the end of the article and exit

Less does not quit

Head: Output file header

NAME
Head-output the first part of the files

[Email protected] ~]# Head/etc/inittab
# Inittab is a used by upstart for the default runlevel.
#
# ADDING Other CONFIGURATION here would have NO EFFECT on YOUR SYSTEM.
#
# System initialization is started by/etc/init/rcs.conf
#
# individual runlevels is started by/etc/init/rc.conf
#
# Ctrl-alt-delete is handled by/etc/init/control-alt-delete.conf
#

Tail: Output File Trailer

NAME
Tail-output the last part of the files

[Email protected] ~]# Tail/etc/inittab
# Default RunLevel. The runlevels used is:
# 0-halt (do not set Initdefault to this)
# 1-single User mode
# 2-multiuser, without NFS (the same as 3, if you don't have networking)
# 3-full Multiuser mode
# 4-unused
# 5-x11
# 6-reboot (do not set Initdefault to this)
#
Id:5:initdefault:
[Email protected] ~]#

-F,--follow[={name|descriptor}] (view trailing append of file)

Output appended data as the file grows; -F,--follow, and--follow=descriptor are
Equivalent

Linux Common Commands-view text/cat,tac,more,less,head,tail