This is Info file ../info/emacs, produced by Makeinfo-1.54 from the input file emacs.texi.  File: emacs, Node: Mayan Calendar, Prev: From Other Calendar, Up: Other Calendars Converting from the Mayan Calendar ---------------------------------- Here are the commands to select dates based on the Mayan calendar: `g m l' Move to a date specified by the long count calendar (`calendar-goto-mayan-long-count-date'). `g m n t' Move to the next occurrence of a place in the tzolkin calendar (`calendar-next-tzolkin-date'). `g m p t' Move to the previous occurrence of a place in the tzolkin calendar (`calendar-previous-tzolkin-date'). `g m n h' Move to the next occurrence of a place in the haab calendar (`calendar-next-haab-date'). `g m p h' Move to the previous occurrence of a place in the haab calendar (`calendar-previous-haab-date'). `g m n c' Move to the next occurrence of a place in the calendar round (`calendar-next-calendar-round-date'). `g m p c' Move to the previous occurrence of a place in the calendar round (`calendar-previous-calendar-round-date'). To understand these commands, you need to understand the Mayan calendars. The "long count" is a counting of days with these units: 1 kin = 1 day 1 uinal = 20 kin 1 tun = 18 uinal 1 katun = 20 tun 1 baktun = 20 katun Thus, the long count date 12.16.11.16.6 means 12 baktun, 16 katun, 11 tun, 16 uinal, and 6 kin. The Emacs calendar can handle Mayan long count dates as early as 7.17.18.13.1, but no earlier. When you use the `g m l' command, type the Mayan long count date with the baktun, katun, tun, uinal, and kin separated by periods. The Mayan tzolkin calendar is a cycle of 260 days formed by a pair of independent cycles of 13 and 20 days. Since this cycle repeats endlessly, Emacs provides commands to move backward and forward to the previous or next point in the cycle. Type `g m p t' to go to the previous tzolkin date; Emacs asks you for a tzolkin date and moves point to the previous occurrence of that date. Similarly, type `g m n t' to go to the next occurrence of a tzolkin date. The Mayan haab calendar is a cycle of 365 days arranged as 18 months of 20 days each, followed a 5-day monthless period. Like the tzolkin cycle, this cycle repeats endlessly, and there are commands to move backward and forward to the previous or next point in the cycle. Type `g m p h' to go to the previous haab date; Emacs asks you for a haab date and moves point to the previous occurrence of that date. Similarly, type `g m n h' to go to the next occurrence of a haab date. The Maya also used the combination of the tzolkin date and the haab date. This combination is a cycle of about 52 years called a *calendar round*. If you type `g m p c', Emacs asks you for both a haab and a tzolkin date and then moves point to the previous occurrence of that combination. Use `g m p c' to move point to the next occurrence of a combination. These commands signal an error if the haab/tzolkin date combination you have typed is impossible. Emacs uses strict completion (*note Strict Completion::.) whenever it asks you to type a Mayan name, so you don't have to worry about spelling.  File: emacs, Node: Diary, Next: Appointments, Prev: Other Calendars, Up: Calendar/Diary The Diary ========= The Emacs diary keeps track of appointments or other events on a daily basis, in conjunction with the calendar. To use the diary feature, you must first create a "diary file" containing a list of events and their dates. Then Emacs can automatically pick out and display the events for today, for the immediate future, or for any specified date. By default, Emacs uses `~/diary' as the diary file. This is the same file that the `calendar' utility uses. A sample `~/diary' file is: 12/22/1988 Twentieth wedding anniversary!! &1/1. Happy New Year! 10/22 Ruth's birthday. * 21, *: Payday Tuesday--weekly meeting with grad students at 10am Supowit, Shen, Bitner, and Kapoor to attend. 1/13/89 Friday the thirteenth!! &thu 4pm squash game with Lloyd. mar 16 Dad's birthday April 15, 1989 Income tax due. &* 15 time cards due. This example uses extra spaces to align the event descriptions of most of the entries. Such formatting is purely a matter of taste. Although you probably will start by creating a diary manually, Emacs provides a number of commands to let you view, add, and change diary entries. * Menu: * Diary Commands:: Viewing diary entries and associated calendar dates. * Format of Diary File:: Entering events in your diary. * Date Formats:: Various ways you can specify dates. * Adding to Diary:: Commands to create diary entries. * Special Diary Entries:: Anniversaries, blocks of dates, cyclic entries, etc.  File: emacs, Node: Diary Commands, Next: Format of Diary File, Up: Diary Commands Displaying Diary Entries --------------------------------- Once you have created a `~/diary' file, you can use the calendar to view it. You can also view today's events outside of Calendar mode. `d' Display all diary entries for the selected date (`view-diary-entries'). `Mouse-2 Diary' Display all diary entries for the date you click on. `s' Display the entire diary file (`show-all-diary-entries'). `m' Mark all visible dates that have diary entries (`mark-diary-entries'). `u' Unmark the calendar window (`calendar-unmark'). `M-x print-diary-entries' Print hard copy of the diary display as it appears. `M-x diary' Display all diary entries for today's date. Displaying the diary entries with `d' shows in a separate window the diary entries for the selected date in the calendar. The mode line of the new window shows the date of the diary entries and any holidays that fall on that date. If you specify a numeric argument with `d', it shows all the diary entries for that many successive days. Thus, `2 d' displays all the entries for the selected date and for the following day. Another way to display the diary entries for a date is to click `Mouse-2' on the date, and then choose `Diary' from the menu that appears. To get a broader view of which days are mentioned in the diary, use the `m' command. This displays the dates that have diary entries fall in a different face (or places a `+' after these dates, if display with multiple faces is not available). The command applies both to the currently visible months and to other months that subsequently become visible by scrolling. To turn marking off and erase the current marks, type `u', which also turns off holiday marks (*note Holidays::.). To see the full diary file, rather than just some of the entries, use the `s' command. Display of selected diary entries uses the selective display feature to hide entries that don't apply. This is the same feature that Outline mode uses to show part of an outline (*note Outline Mode::.). The diary buffer as you see it is an illusion, so simply printing the buffer does not print what you see on your screen. There is a special command to print hard copy of the diary buffer *as it appears*; this command is `M-x print-diary-entries'. It sends the data directly to the printer. You can customize it like `lpr-region' (*note Hardcopy::.). The command `M-x diary' displays the diary entries for the current date, independently of the calendar display, and optionally for the next few days as well; the variable `number-of-diary-entries' specifies how many days to include. *Note Calendar/Diary Options: (elisp)Calendar/Diary Options. If you put `(diary)' in your `.emacs' file, this automatically displays a window with the day's diary entries, when you enter Emacs. The mode line of the displayed window shows the date and any holidays that fall on that date.  File: emacs, Node: Format of Diary File, Next: Date Formats, Prev: Diary Commands, Up: Diary The Diary File -------------- Your "diary file" is a file that records events associated with particular dates. The name of the diary file is specified by the variable `diary-file'; `~/diary' is the default. The `calendar' utility program supports a subset of the format allowed by the Emacs diary facilities, so you can use that utility to view the diary file, with reasonable results aside from the entries it cannot understand. Each entry in the diary file describes one event and consists of one or more lines. An entry always begins with a date specification at the left margin. The rest of the entry is simply text to describe the event. If the entry has more than one line, then the lines after the first must begin with whitespace to indicate they continue a previous entry. Lines that do not begin with valid dates and do not continue a preceding entry are ignored. You can inhibit the marking of certain diary entries in the calendar window; to do this, insert an ampersand (`&') at the beginning of the entry, before the date. This has no effect on display of the entry in the diary window; it affects only marks on dates in the calendar window. Nonmarking entries are especially useful for generic entries that would otherwise mark many different dates. If the first line of a diary entry consists only of the date or day name with no following blanks or punctuation, then the diary window display doesn't include that line; only the continuation lines appear. For example, this entry: 02/11/1989 Bill B. visits Princeton today 2pm Cognitive Studies Committee meeting 2:30-5:30 Liz at Lawrenceville 4:00pm Dentist appt 7:30pm Dinner at George's 8:00-10:00pm concert appears in the diary window without the date line at the beginning. This style of entry looks neater when you display just a single day's entries, but can cause confusion if you ask for more than one day's entries. You can edit the diary entries as they appear in the window, but it is important to remember that the buffer displayed contains the *entire* diary file, with portions of it concealed from view. This means, for instance, that the `C-f' (`forward-char') command can put point at what appears to be the end of the line, but what is in reality the middle of some concealed line. *Be careful when editing the diary entries!* Inserting additional lines or adding/deleting characters in the middle of a visible line cannot cause problems, but editing at the end of a line may not do what you expect. Deleting a line may delete other invisible entries that follow it. Before editing the diary, it is best to display the entire file with `s' (`show-all-diary-entries').  File: emacs, Node: Date Formats, Next: Adding to Diary, Prev: Format of Diary File, Up: Diary Date Formats ------------ Here are some sample diary entries, illustrating different ways of formatting a date. The examples all show dates in American order (month, day, year), but Calendar mode supports European order (day, month, year) as an option. 4/20/93 Switch-over to new tabulation system apr. 25 Start tabulating annual results 4/30 Results for April are due */25 Monthly cycle finishes Friday Don't leave without backing up files The first entry appears only once, on April 20, 1993. The second and third appear every year on the specified dates, and the fourth uses a wildcard (asterisk) for the month, so it appears on the 25th of every month. The final entry appears every week on Friday. You can use just numbers to express a date, as in `MONTH/DAY' or `MONTH/DAY/YEAR'. This must be followed by a nondigit. In the date itself, MONTH and DAY are numbers of one or two digits. The optional YEAR is also a number, and may be abbreviated to the last two digits; that is, you can use `11/12/1989' or `11/12/89'. Dates can also have the form `MONTHNAME DAY' or `MONTHNAME DAY, YEAR', where the month's name can be spelled in full or abbreviated to three characters (with or without a period). Case is not significant. A date may be "generic"; that is, partially unspecified. Then the entry applies to all dates that match the specification. If the date does not contain a year, it is generic and applies to any year. Alternatively, MONTH, DAY, or YEAR can be a `*'; this matches any month, day, or year, respectively. Thus, a diary entry `3/*/*' matches any day in March of any year; so does `march *'. If you prefer the European style of writing dates--in which the day comes before the month--type `M-x european-calendar' while in the calendar, or set the variable `european-calendar-style' to `t' *before* using any calendar or diary command. This mode interprets all dates in the diary in the European manner, and also uses European style for displaying diary dates. (Note that there is no comma after the MONTHNAME in the European style.) To go back to the (default) American style of writing dates, type `M-x american-calendar'. You can use the name of a day of the week as a generic date which applies to any date falling on that day of the week. You can abbreviate the day of the week to three letters (with or without a period) or spell it in full; case is not significant.  File: emacs, Node: Adding to Diary, Next: Special Diary Entries, Prev: Date Formats, Up: Diary Commands to Add to the Diary ---------------------------- While in the calendar, there are several commands to create diary entries: `i d' Add a diary entry for the selected date (`insert-diary-entry'). `i w' Add a diary entry for the selected day of the week (`insert-weekly-diary-entry'). `i m' Add a diary entry for the selected day of the month (`insert-monthly-diary-entry'). `i y' Add a diary entry for the selected day of the year (`insert-yearly-diary-entry'). You can make a diary entry for a specific date by selecting that date in the calendar window and typing the `i d' command. This command displays the end of your diary file in another window and inserts the date; you can then type the rest of the diary entry. If you want to make a diary entry that applies to a specific day of the week, select that day of the week (any occurrence will do) and type `i w'. This inserts the day-of-week as a generic date; you can then type the rest of the diary entry. You can make a monthly diary entry in the same fashion. Select the day of the month, use the `i m' command, and type rest of the entry. Similarly, you can insert a yearly diary entry with the `i y' command. All of the above commands make marking diary entries by default. To make a nonmarking diary entry, give a numeric argument to the command. For example, `C-u i w' makes a nonmarking weekly diary entry. When you modify the diary file, be sure to save the file before exiting Emacs.  File: emacs, Node: Special Diary Entries, Prev: Adding to Diary, Up: Diary Special Diary Entries --------------------- In addition to entries based on calendar dates, the diary file can contain "special entries" for regular events such as anniversaries. These entries are based on Lisp expressions (sexps) that Emacs evaluates as it scans the diary file. Instead of a date, a special entry contains `%%' followed by a Lisp expression which must begin and end with parentheses. The Lisp expression determines which dates the entry applies to. Calendar mode provides commands to insert certain commonly used special entries: `i a' Add an anniversary diary entry for the selected date (`insert-anniversary-diary-entry'). `i b' Add a block diary entry for the current region (`insert-block-diary-entry'). `i c' Add a cyclic diary entry starting at the date (`insert-cyclic-diary-entry'). If you want to make a diary entry that applies to the anniversary of a specific date, move point to that date and use the `i a' command. This displays the end of your diary file in another window and inserts the anniversary description; you can then type the rest of the diary entry. The entry looks like this: %%(diary-anniversary 10 31 1948) Arthur's birthday This entry applies to October 31 in any year after 1948; `10 31 1948' specifies the date. (If you are using the European calendar style, the month and day are interchanged.) The reason this expression requires a beginning year is that advanced diary functions can use it to calculate the number of elapsed years. A "block" diary entry applies to a specified range of consecutive dates. Here is a block diary entry that applies to all dates from June 24, 1990 through July 10, 1990: %%(diary-block 6 24 1990 7 10 1990) Vacation The `6 24 1990' indicates the starting date and the `7 10 1990' indicates the stopping date. (Again, if you are using the European calendar style, the month and day are interchanged.) To insert a block entry, place point and the mark on the two dates that begin and end the range, and type `i b'. This command displays the end of your diary file in another window and inserts the block description; you can then type the diary entry. "Cyclic" diary entries repeat after a fixed interval of days. To create one, select the starting date and use the `i c' command. The command prompts for the length of interval, then inserts the entry, which looks like this: %%(diary-cyclic 50 3 1 1990) Renew medication This entry applies to March 1, 1990 and every 50th day following; `3 1 1990' specifies the starting date. (If you are using the European calendar style, the month and day are interchanged.) All three of these commands make marking diary entries. To insert a nonmarking entry, give a numeric argument to the command. For example, `C-u i a' makes a nonmarking anniversary diary entry. Marking sexp diary entries in the calendar is *extremely* time-consuming, since every date visible in the calendar window must be individually checked. So it's a good idea to make sexp diary entries nonmarking (with `&') when possible. Another sophisticated kind of sexp entry, a "floating" diary entry, specifies a regularly-occurring event by offsets specified in days, weeks, and months. It is comparable to a crontab entry interpreted by the `cron' utility. Here is a nonmarking, floating diary entry that applies to the last Thursday in November: &%%(diary-float 11 4 -1) American Thanksgiving The 11 specifies November (the eleventh month), the 4 specifies Thursday (the fourth day of the week, where Sunday is numbered zero), and the -1 specifies "last" (1 would mean "first", 2 would mean "second", -2 would mean "second-to-last", and so on). The month can be a single month or a list of months. Thus you could change the 11 above to `'(1 2 3)' and have the entry apply to the last Thursday of January, February, and March. If the month is `t', the entry applies to all months of the year. Most generally, special diary entries can perform arbitrary computations to determine when they apply. *Note Sexp Diary Entries: (elisp)Sexp Diary Entries.  File: emacs, Node: Appointments, Next: Daylight Savings, Prev: Diary, Up: Calendar/Diary Appointments ============ If you have a diary entry for an appointment, and that diary entry begins with a recognizable time of day, Emacs can warn you, several minutes beforehand, that that appointment is pending. Emacs alerts you to the appointment by displaying a message in the mode line. To enable appointment notification, you must enable the time display feature of Emacs, `M-x display-time' (*note Mode Line::.). You must also add the function `appt-make-list' to the `diary-hook', like this: (add-hook 'diary-hook 'appt-make-list) With these preparations done, when you display the diary (either with the `d' command in the calendar window or with the `M-x diary' command), it sets up an appointment list of all the diary entries found with recognizable times of day, and reminds you just before each of them. For example, suppose the diary file contains these lines: Monday 9:30am Coffee break 12:00pm Lunch Then on Mondays, after you have displayed the diary, you will be reminded at 9:20am about your coffee break and at 11:50am about lunch. You can write times in conventional American am/pm style, or 24-hour European/military style. You need not be consistent; your diary file can have a mixture of the two styles. Emacs updates the appointments list automatically just after midnight. This also displays the next day's diary entries in the diary buffer, unless you set `appt-display-diary' to `nil'. You can also use the appointment notification facility like an alarm clock. The command `M-x appt-add' adds entries to the appointment list without affecting your diary file. You delete entries from the appointment list with `M-x appt-delete'. You can turn off the appointment notification feature at any time by setting `appt-issue-message' to `nil'.  File: emacs, Node: Daylight Savings, Prev: Appointments, Up: Calendar/Diary Daylight Savings Time ===================== Emacs understands the difference between standard time and daylight savings time--the times given for sunrise, sunset, solstices, equinoxes, and the phases of the moon take that into account. The rules for daylight savings time vary from place to place and have also varied historically from year to year. To do the job properly, Emacs needs to know which rules to use. Some operating systems keep track of the rules that apply to the place where you are; on these systems, Emacs gets the information it needs from the system automatically. If some or all of this information is missing, Emacs fills in the gaps with the rules currently used in Cambridge, Massachusetts. If the resulting rules are not what you want, you can tell Emacs the rules to use by setting certain variables. These values should be Lisp expressions that refer to the variable `year', and evaluate to the Gregorian date on which daylight savings time starts or (respectively) ends, in the form of a list `(MONTH DAY YEAR)'. The values should be `nil' if your area does not use daylight savings time. Emacs uses these expressions to determine the starting date of daylight savings time for the holiday list and for correcting times of day in the solar and lunar calculations. The values for Cambridge, Massachusetts are as follows: (calendar-nth-named-day 1 0 4 year) (calendar-nth-named-day -1 0 10 year) That is, the first 0th day (Sunday) of the fourth month (April) in the year specified by `year', and the last Sunday of the tenth month (October) of that year. If daylight savings time were changed to start on October 1, you would set `calendar-daylight-savings-starts' to this: (list 10 1 year) If there is no daylight savings time at your location, or if you want all times in standard time, set `calendar-daylight-savings-starts' and `calendar-daylight-savings-ends' to `nil'. The variable `calendar-daylight-time-offset' specifies the difference between daylight savings time and standard time, measured in minutes. The value for Cambridge, Massachusetts is 60. The two variables `calendar-daylight-savings-starts-time' and `calendar-daylight-savings-ends-time' specify the number of minutes after midnight local time when the transition to and from daylight savings time should occur. For Cambridge, both variables' values are 120.  File: emacs, Node: GNUS, Next: Shell, Prev: Calendar/Diary, Up: Top GNUS ==== GNUS is an Emacs subsystem for reading and responding to netnews. You can use GNUS to browse through news groups, look at summaries of articles in specific group, and read articles of interest. You can respond to authors or write replies to all the readers of a news group. This section introduces GNUS and describes several basic features. Full documentation will appear elsewhere. To start GNUS, type `M-x gnus RET'. * Menu: * Buffers of GNUS:: The Newsgroups, Summary and Article buffers. * GNUS Startup:: What you should know about starting GNUS. * Summary of GNUS:: A short description of the basic GNUS commands.  File: emacs, Node: Buffers of GNUS, Next: GNUS Startup, Up: GNUS GNUS's Three Buffers -------------------- GNUS creates and uses three Emacs buffers, each with its own particular purpose and its own major mode. The "Newsgroup buffer" contains a list of newsgroups. This is the first buffer that GNUS displays when it starts up. Normally the list contains only the newsgroups to which you subscribe (which are listed in your `.newsrc' file) and which contain unread articles. Use this buffer to select a specific newsgroup. The "Summary buffer" lists the articles in a single newsgroup, including their subjects, their numbers, and who posted them. GNUS creates a Summary buffer for a newsgroup when you select the group in the Newsgroup buffer. Use this buffer to select an article. The "Article buffer" displays the text of an article. You rarely need to select this buffer because you can scroll through it while remaining in the Summary buffer.  File: emacs, Node: GNUS Startup, Next: Summary of GNUS, Prev: Buffers of GNUS, Up: GNUS When GNUS Starts Up ------------------- At startup, GNUS reads your `.newsrc' news initialization file and attempts to communicate with the local news server, which is a repository of news articles. The news server need not be the same computer you are logged in on. If you start GNUS and connect to the server, but do not see any newsgroups listed in the Newsgroup buffer, type `L' to get a listing of all the newsgroups. Then type `u' to unsubscribe from the newsgroups you don't want to read. (You can move point to a particular group using `n' and `p' or the usual Emacs commands.) When you quit GNUS with `q', it automatically records in your `.newsrc' initialization file the subscribed or unsubscribed status of all newsgroups, except for groups you have "killed". (You do not need to edit this file yourself, but you may.) When new newsgroups come into existence, GNUS subscribes to them automatically; if you don't want to read them, use `u' to unsubscribe from them.  File: emacs, Node: Summary of GNUS, Prev: GNUS Startup, Up: GNUS Summary of GNUS Commands ------------------------ Reading news is a two step process: 1. Choose a newsgroup in the Newsgroup buffer. 2. Select articles from the Summary buffer. Each article selected is displayed in the Article buffer in a large window, below the Summary buffer in its small window. Each GNUS buffer has its own special commands, but commands that do the similar things have similar key bindings. Here are commands for the Newsgroup and Summary buffers: `z' In the Newsgroup buffer, suspend GNUS. You can return to GNUS later by selecting the Newsgroup buffer and typing `g' to get newly arrived articles. `q' In the Newsgroup buffer, update your `.newsrc' initialization file and quit GNUS. In the Summary buffer, exit the current newsgroup and return to the Newsgroup buffer. Thus, typing `q' twice quits GNUS. `L' In the Newsgroup buffer, list all the newsgroups available on your news server (except those you have killed). This may be a long list! `l' In the Newsgroup buffer, list only the newsgroups to which you subscribe and which contain unread articles. `u' In the Newsgroup buffer, unsubscribe from (or subscribe to) the newsgroup listed in the line that point is on. When you quit GNUS by typing `q', GNUS lists in your `.newsrc' file which groups you have subscribed to. The next time you start GNUS, you won't see this group initially, because GNUS normally displays only subscribed-to groups. `C-k' In the Newsgroup buffer, "kill" the current line's newsgroup--don't even list it in `.newsrc' from now on. This affects future GNUS sessions as well as the present session. When you quit GNUS by typing `q', GNUS writes information in the file `.newsrc' describing all newsgroups except those you have "killed." `SPC' In the Newsgroup buffer, select the group on the line under the cursor and display the first unread article in that group. In the Summary buffer, * Select the article on the line under the cursor if none is selected. * Scroll the text of the selected article (if there is one). * Select the next unread article if at the end of the current article. Thus, you can move through all the articles by repeatedly typing SPC. `DEL' In the Newsgroup Buffer, move point to the previous newsgroup containing unread articles. In the Summary buffer, scroll the text of the article backwards. `n' Move point to the next unread newsgroup, or select the next unread article. `p' Move point to the previous unread newsgroup, or select the previous unread article. `C-n' `C-p' Move point to the next or previous item, even if it is marked as read. This does not select the article or newsgroup on that line. `s' In the Summary buffer, do an incremental search of the current text in the Article buffer, just as if you switched to the Article buffer and typed `C-s'. `M-s REGEXP RET' In the Summary buffer, search forward for articles containing a match for REGEXP. `C-c C-s C-n' `C-c C-s C-s' `C-c C-s C-d' `C-c C-s C-a' In the Summary buffer, sort the list of articles by number, subject, date, or author. `C-M-n' `C-M-p' In the Summary buffer, read the next or previous article with the same subject as the current article.  File: emacs, Node: Shell, Next: Emacs Server, Prev: GNUS, Up: Top Running Shell Commands from Emacs ================================= Emacs has commands for passing single command lines to inferior shell processes; it can also run a shell interactively with input and output to an Emacs buffer named `*shell*'. `M-! CMD RET' Run the shell command line CMD and display the output (`shell-command'). `M-| CMD RET' Run the shell command line CMD with region contents as input; optionally replace the region with the output (`shell-command-on-region'). `M-x shell' Run a subshell with input and output through an Emacs buffer. You can then give commands interactively. * Menu: * Single Shell:: How to run one shell command and return. * Interactive Shell:: Permanent shell taking input via Emacs. * Shell Mode:: Special Emacs commands used with permanent shell. * History: Shell History. Repeating previous commands in a shell buffer. * Options: Shell Options. Options for customizing Shell mode. * Remote Host:: Connecting to another computer.  File: emacs, Node: Single Shell, Next: Interactive Shell, Up: Shell Single Shell Commands --------------------- `M-!' (`shell-command') reads a line of text using the minibuffer executes it as a shell command in a subshell made just for this command. Standard input for the command comes from the null device. If the shell command produces any output, the output goes into an Emacs buffer named `*Shell Command Output*', which is displayed in another window but not selected. A numeric argument, as in `M-1 M-!', directs this command to insert any output into the current buffer. In that case, point is left before the output and the mark is set after the output. If the shell command line ends in `&', it runs asynchronously. `M-|' (`shell-command-on-region') is like `M-!' but passes the contents of the region as the standard input to the shell command, instead of no input. If a numeric argument is used, meaning insert the output in the current buffer, then the old region is deleted first and the output replaces it as the contents of the region. Both `M-!' and `M-|' use `shell-file-name' to specify the shell to use. This variable is initialized based on your `SHELL' environment variable when Emacs is started. If the file name does not specify a directory, the directories in the list `exec-path' are searched; this list is initialized based on the environment variable `PATH' when Emacs is started. Your `.emacs' file can override either or both of these default initializations. Both `M-!' and `M-|' wait for the shell command to complete. To stop waiting, type `C-g' to quit; that terminates the shell command with the signal `SIGINT'--the same signal that `C-c' normally generates in the shell. Emacs waits until the command actually terminates. If the shell command doesn't stop (because it ignores the `SIGINT' signal), type `C-g' again; this sends the command a `SIGKILL' signal which is impossible to ignore.  File: emacs, Node: Interactive Shell, Next: Shell Mode, Prev: Single Shell, Up: Shell Interactive Inferior Shell -------------------------- To run a subshell interactively, putting its typescript in an Emacs buffer, use `M-x shell'. This creates (or reuses) a buffer named `*shell*' and runs a subshell with input coming from and output going to that buffer. That is to say, any "terminal output" from the subshell goes into the buffer, advancing point, and any "terminal input" for the subshell comes from text in the buffer. To give input to the subshell, go to the end of the buffer and type the input, terminated by RET. Emacs does not wait for the subshell to do anything. You can switch windows or buffers and edit them while the shell is waiting, or while it is running a command. Output from the subshell waits until Emacs has time to process it; this happens whenever Emacs is waiting for keyboard input or for time to elapse. To make multiple subshells, rename the buffer `*shell*' to something different using `M-x rename-uniquely'. Then type `M-x shell' again to create a new buffer `*shell*' with its own subshell. If you rename this buffer as well, you can create a third one, and so on. All the subshells run independently and in parallel. The file name used to load the subshell is the value of the variable `explicit-shell-file-name', if that is non-`nil'. Otherwise, the environment variable `ESHELL' is used, or the environment variable `SHELL' if there is no `ESHELL'. If the file name specified is relative, the directories in the list `exec-path' are searched; this list is initialized based on the environment variable `PATH' when Emacs is started. Your `.emacs' file can override either or both of these default initializations. As soon as the subshell is started, it is sent as input the contents of the file `~/.emacs_SHELLNAME', if that file exists, where SHELLNAME is the name of the file that the shell was loaded from. For example, if you use bash, the file sent to it is `~/.emacs_bash'. `cd', `pushd' and `popd' commands given to the inferior shell are watched by Emacs so it can keep the `*shell*' buffer's default directory the same as the shell's working directory. These commands are recognized syntactically by examining lines of input that are sent. If you use aliases for these commands, you can tell Emacs to recognize them also. For example, if the value of the variable `shell-pushd-regexp' matches the beginning of a shell command line, that line is regarded as a `pushd' command. Change this variable when you add aliases for `pushd'. Likewise, `shell-popd-regexp' and `shell-cd-regexp' are used to recognize commands with the meaning of `popd' and `cd'. These commands are recognized only at the beginning of a shell command line. If Emacs gets an error while trying to handle what it believes is a `cd', `pushd' or `popd' command, it runs the hook `shell-set-directory-error-hook' (*note Hooks::.). If Emacs does not properly track changes in the current directory of the subshell, use the command `M-x dirs' to ask the shell what its current directory is. This command works for shells that support the most common command syntax; it may not work for unusual shells.  File: emacs, Node: Shell Mode, Next: Shell History, Prev: Interactive Shell, Up: Shell Shell Mode ---------- Shell buffer use Shell mode, which defines several special keys attached to the `C-c' prefix. They are chosen to resemble the usual editing and job control characters present in shells that are not under Emacs, except that you must type `C-c' first. Here is a complete list of the special key bindings of Shell mode: `RET' At end of buffer send line as input; otherwise, copy current line to end of buffer and send it (`comint-send-input'). When a line is copied, any text at the beginning of the line that matches the variable `shell-prompt-pattern' is left out; this variable's value should be a regexp string that matches the prompts that your shell uses. `TAB' Complete the command name or file name before point in the shell buffer (`comint-dynamic-complete'). TAB also completes history references (*note History References::.) and environment variable names. The variable `shell-completion-fignore' specifies a list of file name extensions to ignore in Shell mode completion. The default setting ignores file names ending in `~', `#' or `%'. Other related Comint modes use the variable `comint-completion-fignore' instead. `M-?' Display temporarily a list of the possible completions of the file name before point in the shell buffer (`comint-dynamic-list-filename-completions'). `C-d' Either delete a character or send EOF (`comint-delchar-or-maybe-eof'). Typed at the end of the shell buffer, `C-d' sends EOF to the subshell. Typed at any other position in the buffer, `C-d' deletes a character as usual. `C-c C-a' Move to the beginning of the line, but after the prompt if any (`comint-bol'). `C-c C-u' Kill all text pending at end of buffer to be sent as input (`comint-kill-input'). `C-c C-w' Kill a word before point (`backward-kill-word'). `C-c C-c' Interrupt the shell or its current subjob if any (`comint-interrupt-subjob'). `C-c C-z' Stop the shell or its current subjob if any (`comint-stop-subjob'). `C-c C-\' Send quit signal to the shell or its current subjob if any (`comint-quit-subjob'). `C-c C-o' Kill the last batch of output from a shell command (`comint-kill-output'). This is useful if a shell command spews out lots of output that just gets in the way. `C-c C-r' `C-M-l' Scroll to display the beginning of the last batch of output at the top of the window; also move the cursor there (`comint-show-output'). `C-c C-e' Scroll to put the end of the buffer at the bottom of the window (`comint-show-maximum-output'). `C-c C-f' Move forward across one shell command, but not beyond the current line (`shell-forward-command'). The variable `shell-command-regexp' specifies how to recognize the end of a command. `C-c C-b' Move backward across one shell command, but not beyond the current line (`shell-backward-command'). `M-x dirs' Ask the shell what its current directory is, so that Emacs can agree with the shell. `M-x send-invisible RET TEXT RET' Send TEXT as input to the shell, after reading it without echoing. This is useful when a shell command runs a program that asks for a password. Alternatively, you can arrange for Emacs to notice password prompts and turn off echoing for them, as follows: (add-hook `comint-output-filter-functions `comint-watch-for-password-prompt) `M-x comint-continue-subjob' Continue the shell process. This is useful if you accidentally suspend the shell process.(1) `M-x shell-strip-ctrl-m' Discard all control-m characters from the shell output. Shell mode also customizes the paragraph commands so that only shell prompts start new paragraphs. Thus, a paragraph consists of an input command plus the output that follows it in the buffer. Shell mode is a derivative of Comint mode, a general purpose mode for communicating with interactive subprocesses. Most of the features of Shell mode actually come from Comint mode, as you can see from the command names listed above. The specialization of Shell mode in particular include the choice of regular expression for detecting prompts, the directory tracking feature, and a few user commands. Other Emacs features that use variants of Comint mode include GUD (*note Debuggers::.) and `M-x run-lisp' (*note External Lisp::.). You can use `M-x comint-run' to execute any program of your choice in a subprocess using unmodified Comint mode--without the specializations of Shell mode. ---------- Footnotes ---------- (1) You should not suspend the shell process. Suspending a subjob of the shell is a completely different matter--that is normal practice, but you must use the shell to continue the subjob; this command won't do it.  File: emacs, Node: Shell History, Next: Shell Options, Prev: Shell Mode, Up: Shell Shell Command History --------------------- Shell buffers support three ways of repeating earlier commands. You can use the same keys used in the minibuffer; these work much as they do in the minibuffer, inserting text from prior commands while point remains always at the end of the buffer. You can move through the buffer to previous inputs in their original place, then resubmit them or copy them to the end. Or you can use a `!'-style history reference. * Menu: * Ring: Shell Ring. Fetching commands from the history list. * Copy: Shell History Copying. Moving to a command and then copying it. * History References:: Expanding `!'-style history references.  File: emacs, Node: Shell Ring, Next: Shell History Copying, Up: Shell History Shell History Ring .................. `M-p' Fetch the next earlier old shell command. `M-n' Fetch the next later old shell command. `M-r REGEXP RET' `M-s REGEXP RET' Search backwards or forwards for old shell commands that match REGEXP. Shell buffers provide a history of previously entered shell commands. To reuse shell commands from the history, use the editing commands `M-p', `M-n', `M-r' and `M-s'. These work just like the minibuffer history commands except that they operate on the text at the end of the shell buffer, where you would normally insert text to send to the shell. `M-p' fetches an earlier shell command to the end of the shell buffer. Successive use of `M-p' fetches successively earlier shell commands, each replacing any text that was already present as potential shell input. `M-n' does likewise except that it finds successively more recent shell commands from the buffer. The history search commands `M-r' and `M-s' read a regular expression and search through the history for a matching command. Aside from the choice of which command to fetch, they work just like `M-p' and `M-r'. If you enter an empty regexp, these commands reuse the same regexp used last time. When you find the previous input you want, you can resubmit it by typing RET, or you can edit it first and then resubmit it if you wish. These commands get the text of previous shell commands from a special history list, not from the shell buffer itself. Thus, editing the shell buffer, or even killing large parts of it, does not affect the history that these commands access. Some shells store their command histories in files so that you can refer to previous commands from previous shell sessions. Emacs reads the command history file for your chosen shell, to initialize its own command history. The file name is `~/.bash_history' for bash, `~/.sh_history' for ksh, and `~/.history' for other shells.  File: emacs, Node: Shell History Copying, Next: History References, Prev: Shell Ring, Up: Shell History Shell History Copying ..................... `C-c C-p' Move point to the previous prompt (`comint-previous-prompt'). `C-c C-n' Move point to the following prompt (`comint-next-prompt'). `C-c RET' Copy the input command which point is in, inserting the copy at the end of the buffer (`comint-copy-old-input'). This is useful if you move point back to a previous command. After you copy the command, you can submit the copy as input with RET. If you wish, you can edit the copy before resubmitting it. Moving to a previous input and then copying it with `C-c RET' produces the same results--the same buffer contents--that you would get by using `M-p' enough times to fetch that previous input from the history list. However, `C-c RET' copies the text from the buffer, which can be different from what is in the history list if you edit the input text in the buffer after it has been sent.  File: emacs, Node: History References, Prev: Shell History Copying, Up: Shell History Shell History References ........................ Various shells including csh and bash support "history references" that begin with `!' and `^'. Shell mode can understands these constructs and perform the history substitution for you. If you insert a history reference and type TAB, this searches the input history for a matching command, performs substitution if necessary, and places the result in the buffer in place of the history reference. For example, you can fetch the most recent command beginning with `mv' with `! m v TAB'. You can edit the command if you wish, and then resubmit the command to the shell by typing RET. History references take effect only following a shell prompt. The variable `shell-prompt-pattern' specifies how to recognize a shell prompt. Comint modes in general use the variable `comint-prompt-regexp' to specify how to find a prompt; Shell mode uses `shell-prompt-pattern' to set up the local value of `comint-prompt-regexp'. Shell mode can optionally expand history references in the buffer when you send them to the shell. To request this, set the variable `comint-input-autoexpand' to `input'. You can make SPC perform history expansion by binding SPC to the command `comint-magic-space'.  File: emacs, Node: Shell Options, Next: Remote Host, Prev: Shell History, Up: Shell Shell Mode Options ------------------ If the variable `comint-scroll-to-bottom-on-input' is non-`nil', insertion and yank commands scroll the selected window to the bottom before inserting. If `comint-scroll-show-maximum-output' is non-`nil' (which is the default), then scrolling due to arrival of output tries to place the last line of text at the bottom line of the window, so as to show as much useful text as possible. (This mimics the scrolling behavior of many terminals.) By setting `comint-scroll-to-bottom-on-output', you can opt for having point jump to the end of the buffer whenever output arrives--no matter where in the buffer point was before. If the value is `this', point jumps in the selected window. If the value is `all', point jumps in each window that shows the comint buffer. If the value is `other', point jumps in all nonselected windows that show the current buffer. The default value is `nil', which means point does not jump to the end. The variable `comint-input-ignoredups' controls whether successive identical inputs are stored in the input history. A non-`nil' value means to omit an input that is the same as the previous input. The default is `nil', which means to store each input even if it is equal to the previous input. Three variables customize file name completion. The variable `comint-completion-addsuffix' controls whether completion inserts a space or a slash to indicate a fully completed file or directory name (non-`nil' means do insert a space or slash). `comint-completion-recexact', if non-`nil', directs TAB to choose the shortest possible completion if the usual Emacs completion algorithm cannot add even a single character. `comint-completion-autolist', if non-`nil', says to list all the possible completions whenever completion is not exact. The command `comint-dynamic-complete-variable' does variable name completion using the environment variables as set within Emacs. The variables controlling filename completion apply to variable name completion too. This command is normally available through the menu bar. Command completion normally considers only executable files. If you set `shell-command-execonly' to `nil', it considers nonexecutable files as well. You can now configure the behavior of `pushd'. Variables control whether `pushd' behaves like `cd' if no argument is given (`shell-pushd-tohome'), pop rather than rotate with a numeric argument (`shell-pushd-dextract'), and only add directories to the directory stack if they are not already on it (`shell-pushd-dunique'). The values you choose should match the underlying shell, of course.