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)