cmp

cmp command in Linux/UNIX is used to compare the two files byte by byte and helps you to find out whether the two files are identical or not.

• When cmp is used for comparison between two files, it reports the location of the first mismatch to the screen if difference is found and if no difference is found i.e the files compared are identical.
• cmp displays no message and simply returns the prompt if the the files compared are identical.

Syntax:

cmp [OPTION]... FILE1 [FILE2 [SKIP1 [SKIP2]]]

SKIP1 ,SKIP2 & OPTION are optional 
and FILE1 & FILE2 refer to the filenames 

Short Option	Long Option	Option Description
-b	–print-bytes	Print differing bytes.
-i SKIP	–ignore-initial=SKIP	Skip the first SKIP bytes of input
-i SKIP1:SKIP2	–ignore-initial=SKIP1:SKIP2	Skip the first SKIP1 bytes of FILE1 and the first SKIP2 bytes of FILE2.
-	–no-preserve-root	do not treat `/’ specially (the default)
-l	–verbose	Output byte numbers and values of all differing bytes.
-n LIMIT	–bytes=LIMIT	Compare at most LIMIT bytes.
-s	–quiet –silent	Output nothing; yield exit status only.
-v	–version	Output version info.
-	–help	Output this help.

Example

• cmp file1.txt file2.txt

file1.txt file2.txt differ: byte 23, line 1
Can any one explain what is the meaning for byte:23, line 1 in output