cmp MacOS Command Guide

The MacOS cmp command is used to compare two files byte by byte. It provides a way to determine whether two files are identical or different, and it displays the offset and line number of the first differing byte. This command is useful for checking the integrity of files and ensuring data consistency. The syntax of the cmp command is straightforward, and there are several options available to customize its behavior. By understanding how to use the cmp command in MacOS, you can efficiently compare files and identify any discrepancies between them.

cmp Syntax:

cmp [option] file1 file2

Options:

Option	Description
-b, —print-bytes	Print differing bytes as ASCII characters
-i, —ignore-initial	Skip the first N bytes of each file
-l, —verbose	Output byte numbers and differing byte values
-s, —silent	No output is produced
-z, —help	Display help message

Parameters:

Parameter	Description
file1	The first file to compare
file2	The second file to compare

Caution

Take caution when using the cmp command as it directly compares binary data of the two files and can produce unexpected results if not used properly.

cmp Command Samples:

Compare Two Files

cmp file1.txt file2.txt

Compares the contents of file1.txt and file2.txt to check if they are identical.

Ignore Initial ‘n’ Bytes

cmp -n 100 file1.txt file2.txt

Compares the first 100 bytes of file1.txt and file2.txt to check for any differences.

Output Bytes Differing

cmp -l file1.txt file2.txt

Displays the byte number and the differing byte values when comparing file1.txt and file2.txt.

Quiet Mode

cmp -s file1.txt file2.txt

Performs a silent comparison between file1.txt and file2.txt, with no output if the files are identical.

Check for Inequality

cmp -i 10:30 file1.txt file2.txt

Compares the bytes starting from offset 10 up to 30 in file1.txt and file2.txt to check if they are equal.

Report Only Differences

cmp -l file1.txt file2.txt | awk '{print $3}'

Lists only the decimal values of the differing bytes when comparing file1.txt and file2.txt.

Compare Binary Files

cmp -b binaryfile1 binaryfile2

Compares two binary files binaryfile1 and binaryfile2 to check if they are identical.

Tip

When using the cmp command in MacOS, make sure to carefully review the output, especially if there is no response. This command is useful for comparing two files byte by byte, so understanding the differences reported by cmp is crucial.

cmp FAQ:

How do I use cmp in MacOS?

To use the cmp command in MacOS, execute the following command:

cmp file1.txt file2.txt

How can I display only the differing bytes with cmp in MacOS?

To display only the differing bytes when using cmp in MacOS, add the -l flag to the command:

cmp -l file1.txt file2.txt

How do I suppress the output when using cmp in MacOS?

To suppress the output of cmp in MacOS, you can use the -s flag:

cmp -s file1.txt file2.txt

Is there a way to display the total number of differing bytes with cmp in MacOS?

Yes, you can display the total number of differing bytes by using the -n flag followed by the count of differing bytes to display:

cmp -n 10 file1.txt file2.txt

How can I show the line number and byte where the files differ with cmp in MacOS?

To show the line number and byte where the files differ, use the -i flag with the line number where the difference is found:

cmp -i 5 file1.txt file2.txt

Can cmp in MacOS be used to compare binary files?

Yes, cmp in MacOS can be used to compare binary files by specifying the binary files as arguments in the command:

cmp binary1.bin binary2.bin

Applications of the cmp command

• Comparing two files byte by byte
• Checking for differences between two files
• Verifying if two files are identical
• Finding changes in data between two files