{ "content": [ { "type": "text", "text": "# reset (man)\n\n## NAME\n\ntset, reset - initialize or reset terminal state\n\n## SYNOPSIS\n\ntset [-IQVcqrsw] [-] [-e ch] [-i ch] [-k ch] [-m mapping] [terminal-type]\nreset [-IQVcqrsw] [-] [-e ch] [-i ch] [-k ch] [-m mapping] [terminal-type]\n\n## DESCRIPTION\n\ntset — initialization\nThis program initializes terminals.\n\n## TLDR\n\n> Reinitialize the current terminal. Clears the entire terminal screen.\n\n- Reinitialize the current terminal:\n `reset`\n- Display the terminal type instead:\n `reset -q`\n\n*Source: tldr-pages*\n\n## Sections\n\n- **NAME**\n- **SYNOPSIS**\n- **DESCRIPTION** (2 subsections)\n- **OPTIONS** (12 subsections)\n- **ENVIRONMENT**\n- **FILES**\n- **PORTABILITY** (1 subsections)\n- **HISTORY**\n- **SEE ALSO**\n\nUse structuredContent.sections for detailed options, examples, and full documentation.\n" } ], "structuredContent": { "command": "reset", "section": "", "mode": "man", "summary": "tset, reset - initialize or reset terminal state", "synopsis": "tset [-IQVcqrsw] [-] [-e ch] [-i ch] [-k ch] [-m mapping] [terminal-type]\nreset [-IQVcqrsw] [-] [-e ch] [-i ch] [-k ch] [-m mapping] [terminal-type]", "tldr_summary": "Reinitialize the current terminal. Clears the entire terminal screen.", "tldr_examples": [ { "description": "Reinitialize the current terminal", "command": "reset" }, { "description": "Display the terminal type instead", "command": "reset -q" } ], "tldr_source": "official", "flags": [ { "flag": "-c", "long": null, "arg": null, "description": "" }, { "flag": "-e", "long": null, "arg": null, "description": "Set the erase character to ch." }, { "flag": "-I", "long": null, "arg": null, "description": "" }, { "flag": "-i", "long": null, "arg": null, "description": "Set the interrupt character to ch." }, { "flag": "-k", "long": null, "arg": null, "description": "Set the line kill character to ch." }, { "flag": "-m", "long": null, "arg": null, "description": "Specify a mapping from a port type to a terminal; see subsection “Terminal Type Map‐ ping”." }, { "flag": "-Q", "long": null, "arg": null, "description": "tset displays the values for control characters which differ from the system's default values." }, { "flag": "-q", "long": null, "arg": null, "description": "ized in any way. The option “-” by itself is equivalent but archaic." }, { "flag": "-r", "long": null, "arg": null, "description": "" }, { "flag": "-s", "long": null, "arg": null, "description": "standard output; see subsection “Setting the Environment”." }, { "flag": "-V", "long": null, "arg": null, "description": "" }, { "flag": "-w", "long": null, "arg": null, "description": "no effect, unless setupterm is not able to detect the window size. The arguments for the -e, -i, and -k options may either be entered as actual characters or by using the “hat” notation, i.e., control-h may be specified as “^H” or “^h”. If neither -c or -w is given, both options are assumed." } ], "examples": [], "see_also": [ { "name": "csh", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/csh/1/json" }, { "name": "sh", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/sh/1/json" }, { "name": "stty", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/stty/1/json" }, { "name": "terminfo", "section": "3NCURSES", "url": "https://www.chedong.com/phpMan.php/man/terminfo/3NCURSES/json" }, { "name": "tty", "section": "4", "url": "https://www.chedong.com/phpMan.php/man/tty/4/json" }, { "name": "terminfo", "section": "5", "url": "https://www.chedong.com/phpMan.php/man/terminfo/5/json" }, { "name": "ttys", "section": "4", "url": "https://www.chedong.com/phpMan.php/man/ttys/4/json" }, { "name": "environ", "section": "7", "url": "https://www.chedong.com/phpMan.php/man/environ/7/json" } ], "section_outline": [ { "name": "NAME", "lines": 2, "subsections": [] }, { "name": "SYNOPSIS", "lines": 3, "subsections": [] }, { "name": "DESCRIPTION", "lines": 81, "subsections": [ { "name": "Setting the Environment", "lines": 11 }, { "name": "Terminal Type Mapping", "lines": 39 } ] }, { "name": "OPTIONS", "lines": 2, "subsections": [ { "name": "-c", "lines": 1, "flag": "-c" }, { "name": "-e _", "lines": 2, "flag": "-e" }, { "name": "-I", "lines": 1, "flag": "-I" }, { "name": "-i _", "lines": 2, "flag": "-i" }, { "name": "-k _", "lines": 2, "flag": "-k" }, { "name": "-m _", "lines": 3, "flag": "-m" }, { "name": "-Q", "lines": 3, "flag": "-Q" }, { "name": "-q", "lines": 2, "flag": "-q" }, { "name": "-r", "lines": 1, "flag": "-r" }, { "name": "-s", "lines": 2, "flag": "-s" }, { "name": "-V", "lines": 1, "flag": "-V" }, { "name": "-w", "lines": 7, "flag": "-w" } ] }, { "name": "ENVIRONMENT", "lines": 12, "subsections": [] }, { "name": "FILES", "lines": 6, "subsections": [] }, { "name": "PORTABILITY", "lines": 29, "subsections": [ { "name": "-m -a -d -p", "lines": 31, "flag": "-p" } ] }, { "name": "HISTORY", "lines": 16, "subsections": [] }, { "name": "SEE ALSO", "lines": 3, "subsections": [] } ], "sections": { "NAME": { "content": "tset, reset - initialize or reset terminal state\n", "subsections": [] }, "SYNOPSIS": { "content": "tset [-IQVcqrsw] [-] [-e ch] [-i ch] [-k ch] [-m mapping] [terminal-type]\nreset [-IQVcqrsw] [-] [-e ch] [-i ch] [-k ch] [-m mapping] [terminal-type]\n", "subsections": [] }, "DESCRIPTION": { "content": "tset — initialization\nThis program initializes terminals.\n\nFirst, tset retrieves the current terminal mode settings for your terminal. It does this by\nsuccessively testing\n\n• the standard error,\n\n• standard output,\n\n• standard input and\n\n• ultimately “/dev/tty”\n\nto obtain terminal settings. Having retrieved these settings, tset remembers which file de‐\nscriptor to use when updating settings.\n\nNext, tset determines the type of terminal that you are using. This determination is done as\nfollows, using the first terminal type found.\n\n1. The terminal argument specified on the command line.\n\n2. The value of the TERM environment variable.\n\n3. (BSD systems only.) The terminal type associated with the standard error output device in\nthe /etc/ttys file. (On System V hosts and systems using that convention, getty(8) does this\njob by setting TERM according to the type passed to it by /etc/inittab.)\n\n4. The default terminal type, “unknown”, is not suitable for curses applications.\n\nIf the terminal type was not specified on the command-line, the -m option mappings are then\napplied; see subsection “Terminal Type Mapping”. Then, if the terminal type begins with a\nquestion mark (“?”), the user is prompted for confirmation of the terminal type. An empty\nresponse confirms the type, or, another type can be entered to specify a new type. Once the\nterminal type has been determined, the terminal description for the terminal is retrieved.\nIf no terminal description is found for the type, the user is prompted for another terminal\ntype.\n\nOnce the terminal description is retrieved,\n\n• if the “-w” option is enabled, tset may update the terminal's window size.\n\nIf the window size cannot be obtained from the operating system, but the terminal de‐\nscription (or environment, e.g., LINES and COLUMNS variables specify this), use this to\nset the operating system's notion of the window size.\n\n• if the “-c” option is enabled, the backspace, interrupt and line kill characters (among\nmany other things) are set\n\n• unless the “-I” option is enabled, the terminal and tab initialization strings are sent\nto the standard error output, and tset waits one second (in case a hardware reset was is‐\nsued).\n\n• Finally, if the erase, interrupt and line kill characters have changed, or are not set to\ntheir default values, their values are displayed to the standard error output.\n\nreset — reinitialization\nWhen invoked as reset, tset sets the terminal modes to “sane” values:\n\n• sets cooked and echo modes,\n\n• turns off cbreak and raw modes,\n\n• turns on newline translation and\n\n• resets any unset special characters to their default values\n\nbefore doing the terminal initialization described above. Also, rather than using the termi‐\nnal initialization strings, it uses the terminal reset strings.\n\nThe reset command is useful after a program dies leaving a terminal in an abnormal state:\n\n• you may have to type\n\nreset\n\n(the line-feed character is normally control-J) to get the terminal to work, as carriage-\nreturn may no longer work in the abnormal state.\n\n• Also, the terminal will often not echo the command.\n", "subsections": [ { "name": "Setting the Environment", "content": "It is often desirable to enter the terminal type and information about the terminal's capa‐\nbilities into the shell's environment. This is done using the -s option.\n\nWhen the -s option is specified, the commands to enter the information into the shell's envi‐\nronment are written to the standard output. If the SHELL environment variable ends in “csh”,\nthe commands are for csh(1), otherwise, they are for sh(1). The csh commands set and unset\nthe shell variable noglob, leaving it unset. The following line in the .login or .profile\nfiles will initialize the environment correctly:\n\neval `tset -s options ... `\n" }, { "name": "Terminal Type Mapping", "content": "When the terminal is not hardwired into the system (or the current system information is in‐\ncorrect) the terminal type derived from the /etc/ttys file or the TERM environment variable\nis often something generic like network, dialup, or unknown. When tset is used in a startup\nscript it is often desirable to provide information about the type of terminal used on such\nports.\n\nThe -m options maps from some set of conditions to a terminal type, that is, to tell tset “If\nI'm on this port at a particular speed, guess that I'm on that kind of terminal”.\n\nThe argument to the -m option consists of an optional port type, an optional operator, an op‐\ntional baud rate specification, an optional colon (“:”) character and a terminal type. The\nport type is a string (delimited by either the operator or the colon character). The opera‐\ntor may be any combination of “>”, “<”, “@”, and “!”; “>” means greater than, “<” means less\nthan, “@” means equal to and “!” inverts the sense of the test. The baud rate is specified\nas a number and is compared with the speed of the standard error output (which should be the\ncontrol terminal). The terminal type is a string.\n\nIf the terminal type is not specified on the command line, the -m mappings are applied to the\nterminal type. If the port type and baud rate match the mapping, the terminal type specified\nin the mapping replaces the current type. If more than one mapping is specified, the first\napplicable mapping is used.\n\nFor example, consider the following mapping: dialup>9600:vt100. The port type is dialup ,\nthe operator is >, the baud rate specification is 9600, and the terminal type is vt100. The\nresult of this mapping is to specify that if the terminal type is dialup, and the baud rate\nis greater than 9600 baud, a terminal type of vt100 will be used.\n\nIf no baud rate is specified, the terminal type will match any baud rate. If no port type is\nspecified, the terminal type will match any port type. For example, -m dialup:vt100 -m\n:?xterm will cause any dialup port, regardless of baud rate, to match the terminal type\nvt100, and any non-dialup port type to match the terminal type ?xterm. Note, because of the\nleading question mark, the user will be queried on a default port as to whether they are ac‐\ntually using an xterm terminal.\n\nNo whitespace characters are permitted in the -m option argument. Also, to avoid problems\nwith meta-characters, it is suggested that the entire -m option argument be placed within\nsingle quote characters, and that csh users insert a backslash character (“\\”) before any ex‐\nclamation marks (“!”).\n" } ] }, "OPTIONS": { "content": "The options are as follows:\n", "subsections": [ { "name": "-c", "content": "", "flag": "-c" }, { "name": "-e _", "content": "Set the erase character to ch.\n", "flag": "-e" }, { "name": "-I", "content": "", "flag": "-I" }, { "name": "-i _", "content": "Set the interrupt character to ch.\n", "flag": "-i" }, { "name": "-k _", "content": "Set the line kill character to ch.\n", "flag": "-k" }, { "name": "-m _", "content": "Specify a mapping from a port type to a terminal; see subsection “Terminal Type Map‐\nping”.\n", "flag": "-m" }, { "name": "-Q", "content": "tset displays the values for control characters which differ from the system's default\nvalues.\n", "flag": "-Q" }, { "name": "-q", "content": "ized in any way. The option “-” by itself is equivalent but archaic.\n", "flag": "-q" }, { "name": "-r", "content": "", "flag": "-r" }, { "name": "-s", "content": "standard output; see subsection “Setting the Environment”.\n", "flag": "-s" }, { "name": "-V", "content": "", "flag": "-V" }, { "name": "-w", "content": "no effect, unless setupterm is not able to detect the window size.\n\nThe arguments for the -e, -i, and -k options may either be entered as actual characters or by\nusing the “hat” notation, i.e., control-h may be specified as “^H” or “^h”.\n\nIf neither -c or -w is given, both options are assumed.\n", "flag": "-w" } ] }, "ENVIRONMENT": { "content": "The tset command uses these environment variables:\n\nSHELL\ntells tset whether to initialize TERM using sh(1) or csh(1) syntax.\n\nTERM Denotes your terminal type. Each terminal type is distinct, though many are similar.\n\nTERMCAP\nmay denote the location of a termcap database. If it is not an absolute pathname, e.g.,\nbegins with a “/”, tset removes the variable from the environment before looking for the\nterminal description.\n", "subsections": [] }, "FILES": { "content": "/etc/ttys\nsystem port name to terminal type mapping database (BSD versions only).\n\n/etc/terminfo\ncompiled terminal description database directory\n", "subsections": [] }, "PORTABILITY": { "content": "Neither IEEE Std 1003.1/The Open Group Base Specifications Issue 7 (POSIX.1-2008) nor X/Open\nCurses Issue 7 documents tset or reset.\n\nThe AT&T tput utility (AIX, HP-UX, Solaris) incorporated the terminal-mode manipulation as\nwell as termcap-based features such as resetting tabstops from tset in BSD (4.1c), presumably\nwith the intention of making tset obsolete. However, each of those systems still provides\ntset. In fact, the commonly-used reset utility is always an alias for tset.\n\nThe tset utility provides backward compatibility with BSD environments; under most modern\nUnices, /etc/inittab and getty(8) can set TERM appropriately for each dial-up line, obviating\nwhat was tset's most important use. This implementation behaves like 4.4BSD tset, with a few\nexceptions we shall consider now.\n\nA few options are different because the TERMCAP variable is no longer supported under ter‐\nminfo-based ncurses:\n\n• The -S option of BSD tset no longer works; it prints an error message to the standard er‐\nror and dies.\n\n• The -s option only sets TERM, not TERMCAP.\n\nThere was an undocumented 4.4BSD feature that invoking tset via a link named “TSET” (or via\nany other name beginning with an upper-case letter) set the terminal to use upper-case only.\nThis feature has been omitted.\n\nThe -A, -E, -h, -u and -v options were deleted from the tset utility in 4.4BSD. None of them\nwere documented in 4.3BSD and all are of limited utility at best. The -a, -d, and -p options\nare similarly not documented or useful, but were retained as they appear to be in widespread\nuse. It is strongly recommended that any usage of these three options be changed to use the", "subsections": [ { "name": "-m -a -d -p", "content": "above.\n\nVery old systems, e.g., 3BSD, used a different terminal driver which was replaced in 4BSD in\nthe early 1980s. To accommodate these older systems, the 4BSD tset provided a -n option to\nspecify that the new terminal driver should be used. This implementation does not provide\nthat choice.\n\nIt is still permissible to specify the -e, -i, and -k options without arguments, although it\nis strongly recommended that such usage be fixed to explicitly specify the character.\n\nAs of 4.4BSD, executing tset as reset no longer implies the -Q option. Also, the interaction\nbetween the - option and the terminal argument in some historic implementations of tset has\nbeen removed.\n\nThe -c and -w options are not found in earlier implementations. However, a different window\nsize-change feature was provided in 4.4BSD.\n\n• In 4.4BSD, tset uses the window size from the termcap description to set the window size\nif tset is not able to obtain the window size from the operating system.\n\n• In ncurses, tset obtains the window size using setupterm, which may be from the operating\nsystem, the LINES and COLUMNS environment variables or the terminal description.\n\nObtaining the window size from the terminal description is common to both implementations,\nbut considered obsolescent. Its only practical use is for hardware terminals. Generally\nspeaking, a window size would be unset only if there were some problem obtaining the value\nfrom the operating system (and setupterm would still fail). For that reason, the LINES and\nCOLUMNS environment variables may be useful for working around window-size problems. Those\nhave the drawback that if the window is resized, those variables must be recomputed and reas‐\nsigned. To do this more easily, use the resize(1) program.\n", "flag": "-p" } ] }, "HISTORY": { "content": "A reset command written by Kurt Shoens appeared in 1BSD (March 1978). It set the erase and\nkill characters to ^H (backspace) and @ respectively. Mark Horton improved this reset in\n3BSD (October 1979), adding intr, quit, start/stop, and eof characters as well as changing\nthe program to avoid modifying any user settings. That version of reset did not use termcap.\n\nEric Allman wrote a distinct tset command for 1BSD, using a forerunner of termcap called\nttycap. Allman's comments in the source code indicate that he began work in October 1977,\ncontinuing development over the next few years. By late 1979, it had migrated to termcap and\nhandled the TERMCAP variable. Later comments indicate that tset was modified in September\n1980 to use logic copied from the 3BSD “reset” program when it was invoked as reset. This\nversion appeared in 4.1cBSD, late in 1982. Other developers such as Keith Bostic and Jim\nBloom continued to modify tset until 4.4BSD was released in 1993.\n\nThe ncurses implementation was lightly adapted from the 4.4BSD sources to use the terminfo\nAPI by Eric S. Raymond .\n", "subsections": [] }, "SEE ALSO": { "content": "csh(1), sh(1), stty(1), terminfo(3NCURSES), tty(4), terminfo(5), ttys(4), environ(7)\n\nncurses 6.4 2023-12-23 tset(1)", "subsections": [] } } } }