cmp - Compare two files

cmp [-l | -s] [-t] file1 file2 [skip1 [skip2]]

Description

You can use cmp to compare two files. By default, a byte for byte binary comparison is done. If no differences are found, no output is written. If no option flags are specified, cmp writes a message with the byte and line number of the first difference and exits with an error. Bytes and lines are numbered beginning with 1.

Options

-l

(Lower case ell) Write the byte number in decimal and the differing bytes in octal for all differences.

-s

Silent mode where no output is written for differing files; only the exit status is set.

-t

Text mode where the files are opened in text mode and translated to the CCSID of the job before comparing byte for byte.

Operands

The file1 and file2 operands are the two files to be compared byte for byte. The optional skip1 and skip2 are the number of bytes to skip from the beginning of each file, respectively, before the comparison begins.

Environment Variables

cmp is affected by the following environment variables:

QIBM_CMP_FILE_SIZE

Controls the maximum file size in bytes that cmp reads into an internal buffer for better performance. For files larger than the maximum size, cmp reads the files one byte at a time.

Exit Status

• 0 when the files are identical
• 1 when the files are different
• >1 when an error occurred

Related information

• sed - Stream editor
• sort - Sort, merge, or sequence check text files
• split - Split files into pieces
• uniq - Report or filter out repeated lines in a file

1. Find the exact position where two files differ. It is better to place the reference or good file first and then the changed or new file second.

   cmp myApplet.java.old myApplet.java.new