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2017-05-17Add persistence to history of the non-legacy shellFred Hebert
This patch adds a mechanism by which shell history gets stored persistently on disk and gets loaded whenever a new shell session begins. The log files are added to the user's cache directory, with multiple files in it, although the location is configurable. All Erlang instances on a given host will share the same log file. There are two hook points in group.erl that are used: when instantiating the buffer, where we fetch from disk, and when adding a line to the buffer (gets stored). This allows all shell instances to use the same base set of lines when loaded, but to keep their history separate after the fact. As lines are added as you go, a new shell session (with ^G -> s -> c) will have access to previous sessions' lines. The implementation makes use of the disk_log library with a rotating log in order to store data, and allow automated repairs. By default, the feature is disabled and must be turned on through OTP environment variable part of the kernel application. The options include: | Option | Accepted values | Default | Description | | ------------------------ | ----------------- |---------- | -------------------- | | shell_history | enabled, disabled | disabled | turn feature on/off | | shell_history_path | any string | user cache| where to put files | | shell_history_file_bytes | 51200..N bytes | 512kb | max data size (>50kb)| | shell_history_drop | ["q().", ...] | [] | blacklisted lines | A version header is added to the disk_log configuration, allowing changes in the storage format to be enacted in the future (i.e. adding segmentation by node name in the same file, or encoding) without conflict. Log rotation is used with multiple log files to ensure proper enforcement of resizing without too much data loss. Because disk_log does not allow to just flush bits of content on rewrite (it truncates any full file), we instead use a wrap log and try to divide the configured size into up to 10 log files so that every time we rotate a log, we lose only 10% of the data. This remains true for corrupted files that cannot fully be repaired. This many-logs-based approach in turn forces the use of a minimal log size for the `shell_history_file_bytes` configuration, since it has to be divided by 10. The shell history is not loaded for the `user` process which, despite running the group.erl module, does not actually require history as it mostly just forwards IO protocol information.
2016-03-15update copyright-yearHenrik Nord
2015-06-18Change license text to APLv2Bruce Yinhe
2014-10-16kernel,ssh: Add synchronous user_drv protocolLukas Larsson
Added a put_chars_sync to the protocol that can be used to talk to user_drv and made group use it. This is needed in order to guarantee that bytes has been pushed to the tty port when doing something like this: io:format("halting\n"),erlang:halt(0). Before this change the halting message could be lost in the message queue of the user_drv process, this is no longer possible. This commit also fixes ssh_cli as that plugs itself in as a user_drv process. OTP-12240
2013-05-06Fix unmatched_returns warnings in STDLIB and KernelHans Bolinder
2013-01-25Make adjustments for UnicodeHans Bolinder
2013-01-25[stdlib] Remove documentation of Unicode functions in io_libHans Bolinder
The documentation of some Unicode functions in io_lib was committed by mistake.
2013-01-19Add search to Erlang shell's historyFred Hebert
Search mode can be entered by pressing ctrl-r. Enter terms and press ctrl-r again to search backwards, or ctrl-s to then search forward (if you terminal doesn't eat up that one). Press enter to execute the line, or use tab, arrow keys, or other control sequences (^D, ^K, etc.) to exit search mode while remaining on the last found line. Exiting is also possible by pressing the escape key twice. The search mode is a simpler version of the one available in bash or zsh shells. This adds a few modes to the shell (search, on top of none and meta) in group.erl for history search, and a few more in edlin.erl to change the meaning of control sequences while searching.
2013-01-02Make sure the Erlang shell prompt can handle UnicodeHans Bolinder
2010-05-19Merge branch 'dp/shell-line-editing' into devErlang/OTP
* dp/shell-line-editing: Readline-style line edit history OTP-8635 dp/shell-line-editing The shell's line editing has been improved to more resemble the behaviour of readline and other shells. (Thanks to Dave Peticolas)
2010-03-09Readline-style line edit historyDave Peticolas
Change the shell's line buffer mechanism to more closely match readline-based shells. New behavior: 1. Blank lines are not added to the line buffer. 2. Pressing the down arrow on the last line causes no change. The previous behavior erased the line. 3. The new line is temporarily added to the line buffer so the user can move to previous lines with up arrows and then back to the new line with down arrows. The previous behavior discarded the partially written new line. 4. Changes made to previous lines while exploring the line buffer history are preserved. The previous behavior discarded changes made to older lines.
2009-11-20The R13B03 release.OTP_R13B03Erlang/OTP