Your Guide to Basic Linux Commands Day06

grep

The grep is used to identify patterns in a file and show the lines that match the pattern. This also includes its switches:

• grep -v = shows the lines that does not match the pattern
• grep -i = searches through the file with case insensitive

Examples:

grep "is" file01.txt
grep -i "error" logfile.txt

wc

The wc or word count command displays the number of lines, words
, letters in the given file. It's switches consist of:

• wc -m = prints the character counts
• wc -l = prints the number of lines

Examples:

wc linuxfile.txt
wc -m linuxfile.txt

sort

The sort filter can be used to show the output in a sorted order in the terminal. It will not actually sort the order within the file. Sort has so many switches but few of them are:

• sort -f = is case insensitive when it comes to sorting
• sort -n = compare and sort according to numerical value

Example:

sort file01.txt
sort -f file01.txt

uniq

The uniq command displays only the unique contents within the file. It has quite a few switches namely:

• uniq -c = prints the count of occurrence of a word
• uniq -i = ignores the case sensitive

Example:

cat file01.txt | uniq
sort file01.txt | uniq -c 

whoami

This command displays the current user of the system.

Example:
whoami