{ "mode": "man", "parameter": "scan", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/scan/1/json", "generated": "2026-08-08T10:40:44Z", "synopsis": "scan [-help] [-version] [+folder] [msgs] [-clear | -noclear] [-form formatfile] [-format\nstring] [-header | -noheader] [-width columns] [-reverse | -noreverse] [-file filename]", "sections": { "NAME": { "content": "scan - produce a summary listing of nmh messages\n", "subsections": [] }, "SYNOPSIS": { "content": "scan [-help] [-version] [+folder] [msgs] [-clear | -noclear] [-form formatfile] [-format\nstring] [-header | -noheader] [-width columns] [-reverse | -noreverse] [-file filename]\n", "subsections": [] }, "DESCRIPTION": { "content": "scan produces a one-line-per-message listing of the specified folder or messages. Each scan\nline contains the message number (name), the date, the “From:” field, the “Subject” field,\nand, if room allows, some of the body of the message. For example:\n\n15+ 10/05 crocker nned <>” if the body is sufficiently\nshort. scan actually reads each of the specified messages and parses them to extract the de‐\nsired fields. During parsing, appropriate error messages will be produced if there are for‐\nmat errors in any of the messages.\n\nBy default, scan will decode RFC 2047 (MIME) encoding in these scan listings. scan will only\ndecode these fields if your terminal can natively display the character set used in the en‐\ncoding. You should set the appropriate locale(1) environment variables to your native char‐\nacter set, if it is not US-ASCII. See locale(1) for more details on the appropriate environ‐\nment variables.\n\nThe switch -reverse, makes scan list the messages in reverse order.\n\nThe -file filename switch allows the user to obtain a scan listing of a mail drop. This\nlisting includes every message in the mail drop (you can't scan individual messages). The\nswitch -reverse is ignored with this option. If filename is a file, it can be in mbox or\nMMDF format, as produced by packf. If filename is a directory, it is considered to be in\nMaildir format.\n\nThe switch -width columns may be used to specify the width of the scan line. The default is\nto use the width of the terminal.\n\nThe -header switch produces a header line prior to the scan listing. Currently, the name of\nthe folder and the current date and time are output (see the HISTORY section for more infor‐\nmation).\n\nIf the -clear switch is used and scan's output is directed to a terminal, then scan will con‐\nsult the environment variables $TERM and $TERMCAP to determine your terminal type in order to\nfind out how to clear the screen prior to exiting. If the -clear switch is used and scan's\noutput is not directed to a terminal (e.g., a pipe or a file), then scan will send a formfeed\nprior to exiting.\n\nFor example, the command:\n\n(scan -clear -header; show all -show pr -f) | lpr\n\nproduces a scan listing of the current folder, followed by a formfeed, followed by a format‐\nted listing of all messages in the folder, one per page. Omitting “-show pr -f” will cause\nthe messages to be concatenated, separated by a one-line header and two blank lines.\n\nTo override the output format used by scan, the -format string or -form file switches are\nused. This permits individual fields of the scan listing to be extracted with ease. The\nstring is simply a format string and the file is simply a format file. See mh-format(5) for\nthe details.\n\nIn addition to the standard mh-format(5) escapes, scan also recognizes the following addi‐\ntional component escapes:\n\nEscape Returns Description\nbody string the (compressed) first part of the body\ndtimenow date the current date\nfolder string the name of the current folder\n\n{body} returns a string without MIME decoding, i.e. the MIME boundary separator may be the\nfirst text shown.\n\nIf no date header is present in the message, the function escapes which operate on {date}\nwill return values for the date of last modification of the message file itself. This fea‐\nture is handy for scanning a draft folder, as message drafts usually aren't allowed to have\ndates in them.\n\nThe /etc/nmh directory contains several format files as examples of customized scan output.\n\nscan will update the nmh context prior to starting the listing, so interrupting a long scan\nlisting preserves the new context. nmh purists hate this idea.\n", "subsections": [] }, "FILES": { "content": "$HOME/.mhprofile The user profile\n", "subsections": [] }, "PROFILE COMPONENTS": { "content": "Path: To determine the user's nmh directory\nAlternate-Mailboxes: To determine the user's mailboxes\nCurrent-Folder: To find the default current folder\n", "subsections": [] }, "SEE ALSO": { "content": "pick(1), show(1), mh-format(5)\n", "subsections": [] }, "DEFAULTS": { "content": "`+folder' defaults to the current folder\n`msgs' defaults to all\n`-format' defaulted as described above\n`-noheader'\n`-width' defaulted to the width of the terminal\n", "subsections": [] }, "CONTEXT": { "content": "If a folder is given, it will become the current folder.\n", "subsections": [] }, "HISTORY": { "content": "Prior to using the format string mechanism, -header used to generate a heading saying what\neach column in the listing was. Format strings prevent this from happening.\n", "subsections": [] }, "BUGS": { "content": "The value of each component escape is set by scan to the contents of the first message header\nscan encounters with the corresponding component name; any following headers with the same\ncomponent name are ignored.\n\nnmh-1.8 2020-02-17 SCAN(1mh)", "subsections": [] } }, "summary": "scan - produce a summary listing of nmh messages", "flags": [], "examples": [], "see_also": [ { "name": "pick", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/pick/1/json" }, { "name": "show", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/show/1/json" }, { "name": "mh-format", "section": "5", "url": "https://www.chedong.com/phpMan.php/man/mh-format/5/json" } ] }