Master Linux Text Viewing: Essential Commands and Practical Tips

Full‑text display with cat

The cat command outputs an entire file to the terminal. Basic usage:

cat file               # display full content
cat -n file            # display with line numbers

It can also concatenate files:

cat file1 file2 >file3   # merge file1 and file2 into file3

Reverse display with tac

tac

is cat reversed; it prints a file line‑by‑line in reverse order.

tac file

Paginated view with more

more

shows a file page by page, useful for large files. more file Common navigation keys:

Enter – scroll down one line (default)

Space – scroll down one screen

b – scroll up one screen

= – display current line number

:f – show file name and line number

q – quit

Start from a specific line: more +10 file # start display at line 10 Start from a matching string:

more +/string file   # start two lines before the line containing "string"

Interactive browsing with less

less

provides forward and backward navigation, plus powerful search.

less file          # view file
less -N file       # view with line numbers
less -m file       # view with percentage progress

Key bindings:

f – forward one screen

b – backward one screen

Enter or j – forward one line

k – backward one line

G – go to the last line

g – go to the first line

/string – search forward for "string"

?string – search backward for "string"

q – quit

Switch between multiple files:

less file1 file2 file3
:n   # next file
:p   # previous file
:x   # first file
:d   # remove current file from the list

Show file header with head

head

displays the beginning of a file.

head -n 100 file   # first 100 lines
head -n -100 file # all but the last 100 lines

Show file tail with tail

tail

displays the end of a file and can follow updates.

tail -100 file          # last 100 lines
tail -n +100 file       # from line 100 onward
tail -f logFile         # continuously display new lines as the file grows

Sorted display with sort

sort

orders lines in a file. Examples:

# Ascending (default)
sort test.txt
# Descending
sort -r test.txt
# Remove duplicate lines
sort -u test.txt
# Numeric sort
sort -n file

Use -r for reverse order, -u to drop duplicates, and -n for numeric comparison.

Filtering with sed

sed

is a stream editor; here we show only viewing‑related features.

# Print lines containing a keyword
sed -n "/string/p" logFile
# Print specific line ranges
sed -n "1,5p" logFile          # lines 1‑5
sed -n "'3,5{=;p}'" logFile   # lines 3‑5 with line numbers
sed -n "10p" logFile           # line 10 only

Remove duplicate lines with uniq

uniq

filters adjacent duplicate lines.

uniq file               # drop duplicate lines
uniq -c file            # show duplicate count
uniq -d file            # only duplicated lines
uniq -u file            # only unique lines
uniq -i file            # ignore case
uniq -w 10 file         # compare first 10 characters

Quick file view with vi

Open a file in the classic editor: vi file For more powerful editing, consider vim, which extends vi with many features (not covered here).

Conclusion

Linux offers a rich set of text‑viewing utilities. Choose the command that matches your workflow—simple display with cat, paginated browsing with more or less, selective extraction with head / tail, sorting with sort, filtering with sed, deduplication with uniq, or quick editing with vi. For deeper options, consult the manual pages.