{
    "mode": "man",
    "parameter": "wrjpgcom",
    "section": "1",
    "url": "https://www.chedong.com/phpMan.php/man/wrjpgcom/1/json",
    "generated": "2026-06-03T01:50:10Z",
    "synopsis": "wrjpgcom [ -replace ] [ -comment text ] [ -cfile name ] [ filename ]",
    "sections": {
        "NAME": {
            "content": "wrjpgcom - insert text comments into a JPEG file\n",
            "subsections": []
        },
        "SYNOPSIS": {
            "content": "wrjpgcom [ -replace ] [ -comment text ] [ -cfile name ] [ filename ]\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "wrjpgcom  reads the named JPEG/JFIF file, or the standard input if no file is named, and gen‐\nerates a new JPEG/JFIF file on standard output.  A comment block is added to the file.\n\nThe JPEG standard allows \"comment\" (COM) blocks to occur within a JPEG  file.   Although  the\nstandard  doesn't actually define what COM blocks are for, they are widely used to hold user-\nsupplied text strings.  This lets you add annotations, titles, index terms, etc to your  JPEG\nfiles, and later retrieve them as text.  COM blocks do not interfere with the image stored in\nthe JPEG file.  The maximum size of a COM block is 64K, but you can have as many of  them  as\nyou like in one JPEG file.\n\nwrjpgcom  adds a COM block, containing text you provide, to a JPEG file.  Ordinarily, the COM\nblock is added after any existing COM blocks; but you can delete the old COM  blocks  if  you\nwish.\n",
            "subsections": []
        },
        "OPTIONS": {
            "content": "Switch names may be abbreviated, and are not case sensitive.\n",
            "subsections": [
                {
                    "name": "-replace",
                    "content": "Delete any existing COM blocks from the file.\n"
                },
                {
                    "name": "-comment",
                    "content": "Supply text for new COM block on command line.\n"
                },
                {
                    "name": "-cfile",
                    "content": "Read text for new COM block from named file.\n\nIf you have only one line of comment text to add, you can provide it on the command line with"
                },
                {
                    "name": "-comment",
                    "content": "argument.  Longer comments can be read from a text file.\n\nIf  you give neither -comment nor -cfile, then wrjpgcom will read the comment text from stan‐\ndard input.  (In this case an input image file name MUST be supplied, so that the source JPEG\nfile  comes  from  somewhere else.)  You can enter multiple lines, up to 64KB worth.  Type an\nend-of-file indicator (usually control-D) to terminate the comment text entry.\n\nwrjpgcom will not add a COM block if the provided comment string is  empty.   Therefore  -re‐‐\nplace -comment \"\" can be used to delete all COM blocks from a file.\n"
                }
            ]
        },
        "EXAMPLES": {
            "content": "Add a short comment to in.jpg, producing out.jpg:\n\nwrjpgcom -c \"View of my back yard\" in.jpg > out.jpg\n\nAttach a long comment previously stored in comment.txt:\n\nwrjpgcom in.jpg < comment.txt > out.jpg\n\nor equivalently\n\nwrjpgcom -cfile comment.txt < in.jpg > out.jpg\n",
            "subsections": []
        },
        "SEE ALSO": {
            "content": "cjpeg(1), djpeg(1), jpegtran(1), rdjpgcom(1)\n",
            "subsections": []
        },
        "AUTHOR": {
            "content": "Independent JPEG Group\n\n\n\n15 June 1995                                 WRJPGCOM(1)",
            "subsections": []
        }
    },
    "summary": "wrjpgcom - insert text comments into a JPEG file",
    "flags": [
        {
            "flag": "",
            "long": null,
            "arg": null,
            "description": "Delete any existing COM blocks from the file."
        },
        {
            "flag": "",
            "long": null,
            "arg": null,
            "description": "Supply text for new COM block on command line."
        },
        {
            "flag": "",
            "long": null,
            "arg": null,
            "description": "Read text for new COM block from named file. If you have only one line of comment text to add, you can provide it on the command line with"
        },
        {
            "flag": "",
            "long": null,
            "arg": null,
            "description": "argument. Longer comments can be read from a text file. If you give neither -comment nor -cfile, then wrjpgcom will read the comment text from stan‐ dard input. (In this case an input image file name MUST be supplied, so that the source JPEG file comes from somewhere else.) You can enter multiple lines, up to 64KB worth. Type an end-of-file indicator (usually control-D) to terminate the comment text entry. wrjpgcom will not add a COM block if the provided comment string is empty. Therefore -re‐‐ place -comment \"\" can be used to delete all COM blocks from a file."
        }
    ],
    "examples": [
        "Add a short comment to in.jpg, producing out.jpg:",
        "wrjpgcom -c \"View of my back yard\" in.jpg > out.jpg",
        "Attach a long comment previously stored in comment.txt:",
        "wrjpgcom in.jpg < comment.txt > out.jpg",
        "or equivalently",
        "wrjpgcom -cfile comment.txt < in.jpg > out.jpg"
    ],
    "see_also": [
        {
            "name": "cjpeg",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/cjpeg/1/json"
        },
        {
            "name": "djpeg",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/djpeg/1/json"
        },
        {
            "name": "jpegtran",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/jpegtran/1/json"
        },
        {
            "name": "rdjpgcom",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/rdjpgcom/1/json"
        }
    ]
}