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 comp(CMD)                       19 June 1992                       comp(CMD)


 Name

    comp - compare the contents of two files or sets of files byte by byte

 Syntax


    comp [data1] [data2] [/d] [/a] [/l] [/n=number] [/c]


 Description

    comp can compare files on the same drive or on different drives, in the
    same directory or in different directories.  As comp compares the files,
    it displays their locations and filenames.

 Parameters


    data1  Specifies the location and name of the first file or set of files
           you want to compare.  You can use wildcards (* and ?) to specify
           multiple files.

    data2  Specifies the location and name of the second file or set of files
           you want to compare.  You can use wildcards (* and ?) to specify
           multiple files.


 Switches


    /d     Displays differences in decimal format.  (The default format is
           hexadecimal.)

    /a     Displays differences as characters.

    /l     Displays the number of the line on which a difference occurs,
           instead of displaying the byte offset.

    /n=number
           Compares the first number of lines of both files, even if the
           files are different sizes.

    /c     Performs a comparison that is not case-sensitive.


 Notes


    Comparing files with the same names

    The files you want to compare can have the same filename, provided they
    are in different directories or on different drives.  If you do not
    specify a filename for data2, the default filename for data2 is the same
    as the filename in data1.  You can use wildcards (* and ?) to specify
    filenames.

    Special cases for data1 and data2

    If you omit necessary components of either data1 or data2 or if you omit
    data2, comp prompts you for the missing information.  If data1 contains
    only a drive letter or a directory name with no filename, the default
    filename for data1 is *.*.  Therefore, comp compares all the files in the
    specified directory to the file specified in data2.  If data2 contains
    only a drive letter or a directory name, the default filename for data2
    is the same as that in data1.

    How the comp command identifies mismatching information

    During the comparison, comp displays messages to identify the locations
    of unequal information in the two files.  Each message indicates the
    offset memory address of the unequal bytes and the contents of the bytes
    themselves (in hexadecimal notation unless you specify the /a or /d
    switch).  The message has the following format:

       Compare error at OFFSET xxxxxxxx

       file1 = xx

       file2 = xx

    After 10 unequal comparisons, comp stops comparing the files and displays
    the following message:

       10 Mismatches - ending compare


    Comparing files of different sizes

    You cannot compare files of different sizes unless you specify the /n
    switch.  If the file sizes are different, comp displays the following
    message:

       Files are different sizes

       Compare more files (Y/N)?


    Press Y to compare another pair of files.  Press N to stop the comp com-
    mand.

    If you press Y in response to the prompt, comp includes any switches you
    specified on the command line in every comparison it makes, until you
    press N or retype the command.

    When comparing files of different sizes, use the /n switch to compare
    only the first portion of each file.

    Comparing files sequentially

    If you use wildcards to specify multiple files, comp finds the first file
    matching data1 and compares it with the corresponding file in data2, if
    it exists.  comp reports the results of the comparison, then does the
    same for each file matching data1.  When finished, comp displays the fol-
    lowing message:

       Compare more files (Y/N)?


    To compare more files, press Y.  comp prompts you for the locations and
    names of the new files.  To stop the comparisons, press N.  When you
    press Y, comp prompts you for switches to use.  If you do not specify any
    switches, comp uses the ones you specified before.

    If comp cannot find the files

    If comp cannot find the file(s) you specify, it prompts you with a mes-
    sage to determine whether you want to compare more files.

 Related commands

    For information about comparing the contents of two floppy disks, see the
    diskcomp(CMD) command.

    For information about doing a complete comparison of two files of dif-
    ferent sizes, see the fc(CMD) command.


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