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EXIFCOM(1)             DragonFly General Commands Manual            EXIFCOM(1)


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)

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