May 12, 2010

"fc" Command

FC (File Compare) is used to compare two files against each other. Once completed, FC will return lines that differ between the two files. If no lines differ, you will receive a message indicating no differences encountered. The fc.exe is an external command that is available in MS-DOS 3.3x and above, Windows 95, Windows 98, Windows ME, Windows NT, Windows 2000, Windows XP, Windows Vista and Windows 7.

Syntax: Compares two files or sets of files and displays the differences between them.
  • FC [switches] [/nnnn] [drive1:][path1]filename1 [drive2:][path2]filename2
  • FC /B [drive1:][path1]filename1 [drive2:][path2]filename2
Switches
  • /A - Displays only first and last lines for each set of differences.
  • /B - Performs a binary comparison.
  • /C - Disregards the case of letters.
  • /L - Compares files as ASCII text.
  • /LBn - Sets the maximum consecutive mismatches to the specified number of lines.
  • /N - Displays the line numbers on an ASCII comparison.
  • /T - Does not expand tabs to spaces.
  • /W - Compresses white space (tabs and spaces) for comparison.
  • /nnn - Specifies the number of consecutive lines that must match after a mismatch.
  • [drive1:][path1]filename1 - Specifies the first file or set of files to compare.
  • [drive2:][path2]filename2 - Specifies the second file or set of files to compare.
Examples
  • fc c:\autoexec.bat c:\config.sys - Give a file comparison between the the config.sys and the autoexec.bat in the current directory.
  • fc c:\autoexec.bat c:\config.sys /b - Give a file comparison between the the config.sys and the autoexec.bat in the current directory in binary format.