NAME

       exifcom - display or set the UserComment tag contained in a JPEG Exif section

SYNOPSIS

       exifcom [ -bfinv ] [ -w comment ] [ -s delim ] file ...

DESCRIPTION

       When  invoked  without  arguments,  the exifcom utility displays the contents of the Exif UserComment tag
       contained in file to the standard output.  Otherwise, depending on the options  specified,  exifcom  will
       blank the tag or set it to comment.

       Some  digital  cameras  include a standard UserComment tag in the Exif data added to the image files they
       produce.  This comment tag is fixed-length and supports multi-byte character sets  (though  exifcom  does
       not).  Note that not all cameras will include the tag.

       The  utility is conservative in its approach to writing the UserComment tag.  It does not modify, extend,
       or otherwise adulterate an image's Exif metadata structure.  When writing the tag it merely changes  pre-
       allocated  bytes.   Therefore,  exifcom is at the mercy of the Exif data creator for both the presence of
       the tag and its length.  It cannot create a UserComment tag when the camera does not include one, nor can
       it  write  a comment longer than the space pre-allocated by the camera.  exifcom only displays and writes
       ASCII character set comments.

OPTIONS

       -b     Blank the UserComment tag, overwriting both the character code and comment fields with  NUL.   The
              character  code  specifies  how the comment is represented; it is "undefined" when blank.  This is
              the state to which many cameras initialize the tag.  When used in conjunction with the -w  option,
              exifcom will blank the comment prior to setting it to comment.

       -f     Overwrite or blank existing or unsupported comments without prompting for confirmation.

       -i     Write  a  prompt  to  standard  error  before  overwriting  or blanking an existing or unsupported
              comment.  If the response from the  standard  input  begins  with  'y'  or  'Y',  the  comment  is
              overwritten.  This option is default behavior.

       -n     Do  not  overwrite  or  blank  existing or unsupported comments and do not prompt for confirmation
              (i.e., automatically answer 'no' to a confirmation prompt).  This  option  takes  precedence  over
              both the -f and -i options.

       -s     Separate  field  name and value in the verbose and multiple file cases with the string delim.  The
              default is ': '.

       -v     Be verbose when printing the contents of the UserComment tag.   Besides  the  comment  itself  (if
              present  and  supported), exifcom will display the maximum comment length supported, the character
              code of the comment, and the length of the comment.

       -w     Set UserComment to the ASCII string comment.  If comment is longer than what the tag supports,  it
              will be truncated to fit.

DIAGNOSTICS

       The exifcom utility exits 0 on success.  When displaying a comment from a single file, if the UserComment
       tag is missing, it exits 1; if blank, it exits 2; if in  an  unsupported  character  code,  it  exits  3.
       Otherwise, it exits 1 if an error occurs.

SEE ALSO

       exiftags(1), exiftime(1)

STANDARDS

       The   exifcom   utility   was   developed   using   the   January   2002   Exif   standard,  version  2.2
       (http://tsc.jeita.or.jp/).

BUGS

       If the tag doesn't exist or is too short, too bad.

AUTHOR

       The exifcom utility and this man page were written by Eric M. Johnston <emj@postal.net>.

                                                                                                      EXIFCOM(1)