The description below is from the book DOS the Easy Way by Everett Murdock Ph.D.
CLICK HERE for information about downloading the book.
Type: External (3.3 and later)
FC [d:][path]filename [d:][path]filename [/A][/C][/L][/Lb n]
or (for binary comparisons)
FC [d:][path]filename [d:][path]filename [/B][/number]
Purpose: Displays the differences between two files or sets of
FC reports differences between the two files you specify. FC first
name of the first file to compare. Next, it displays the lines that
between the two files. Next, it displays the first line that matches in
files. FC next displays the name of the second file, followed by the
are different followed by the first line that matches.
The FC command requires enough system memory (RAM) to compare 100 lines.
system memory is limited, FC will make comparisons between the number of
that can fit into available memory. Be aware that this can change the
of a comparison.
/A - Instead of displaying all the lines that do not match (in an
comparison), the program displays only the lines that begin and end each
/B - Used for a binary comparison of files. The files are compared
byte-by-byte. Mismatches are displayed as a relative address from the
of the file. Unless you specify the /L switch, the program will
assume you want to use this type of comparison when the compared files
.COM, .EXE, .SYS, .BIN, .OBJ, or .LIB filename extension.
/C - Ignores the case of letters in the compared files. All letters
considered as upper case.
/L - Used for an ASCII comparison of files. Unless you specify the /B
switch, the program will automatically assume you want to use this type
comparison for all files that do not have a .COM, .EXE, .SYS, .BIN, .OBJ,
.LIB filename extension.
/Lb n - Sets the line buffer to n number of lines. The amount of
used for holding lines being compared is normally enough to store about
lines. Use this option to reset the buffer (memory space) to n lines.
than this number of consecutive lines is found to differ, the program
terminate the comparison and display an error message.
/N - Used to turn on the display of line numbers while carrying out
/T - Turn off the display of tabs as spaces in an eight column
/W - Compresses tabs and spaces during the comparison.
/(number) - The number of lines that must match after the program finds
difference between the compared files (if fewer lines match, the matching
are displayed as differences). If you do not use this option, the number
lines to match between the files is two.
To compare the text file LETTER.TXT with the file MEMO2.TXT on drive B
fc /l letter.txt b:memo2.txt
To carry out a binary comparison of the files CHECK.EXE and CHECK2.EXE,
fc /b check.exe check2.exe