What uses the TERM variable?Colors in Man PagesHow do keyboard input and text output work?Which terminal type am I using?What protocol/standard is used by terminals?How does a program decide whether or not to have coloured output?Difference between the terminal file and the terminal screenWhat's the difference between various $TERM variables?emacs colors based on $TERM environment variableEmacs Key-binding and the TERM variableWhat's the right value of $TERM for emacs' ansi-term, especially if 'eterm-color' isn't available after SSH?Is it correct to set the $TERM variable manually?Modular $TERM for different terminal emulatorsterm definitions not foundWhere does the TERM environment variable default get set?Why does tmux set TERM variable to screen?
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What uses the TERM variable?
Colors in Man PagesHow do keyboard input and text output work?Which terminal type am I using?What protocol/standard is used by terminals?How does a program decide whether or not to have coloured output?Difference between the terminal file and the terminal screenWhat's the difference between various $TERM variables?emacs colors based on $TERM environment variableEmacs Key-binding and the TERM variableWhat's the right value of $TERM for emacs' ansi-term, especially if 'eterm-color' isn't available after SSH?Is it correct to set the $TERM variable manually?Modular $TERM for different terminal emulatorsterm definitions not foundWhere does the TERM environment variable default get set?Why does tmux set TERM variable to screen?
.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty margin-bottom:0;
According to this document:
The environment variable TERM contains a identifier for the text
window’s capabilities. You can get a detailed list of these
cababilities by using the ‘infocmp’ command, using ‘man 5 terminfo’ as
a reference.
But how is the TERM variable actually used? Say, the system runs xterm (terminal emulator for the X Window System). Does xterm use the TERM variable, or is it the shell? If so, how? Would xterm stop working, if TERM is set to linux?
Also, why isn't colored output disabled if I change TERM from its default value of xterm-256color to something else like xterm?
terminal xterm
edited Jul 4 at 17:12
mosvy
14.9k2 gold badges18 silver badges49 bronze badges
asked Jul 4 at 7:00
ShuzhengShuzheng
2091 silver badge8 bronze badges
add a comment |
According to this document:
The environment variable TERM contains a identifier for the text
window’s capabilities. You can get a detailed list of these
cababilities by using the ‘infocmp’ command, using ‘man 5 terminfo’ as
a reference.
But how is the TERM variable actually used? Say, the system runs xterm (terminal emulator for the X Window System). Does xterm use the TERM variable, or is it the shell? If so, how? Would xterm stop working, if TERM is set to linux?
Also, why isn't colored output disabled if I change TERM from its default value of xterm-256color to something else like xterm?
terminal xterm
edited Jul 4 at 17:12
mosvy
14.9k2 gold badges18 silver badges49 bronze badges
asked Jul 4 at 7:00
ShuzhengShuzheng
2091 silver badge8 bronze badges
These questions are way too broad, and an answer will turn into a treatise, but for the last of them it's simple: GNUlsandgrepdo NOT care about the TERM variable, they simply assume that any terminal supports ANSI color escapes.
– Uncle Billy
Jul 4 at 7:24
1
You can use this occasion to submit a doc patch to gettext to fix the spelling of "cababilities" in that manual.
– Uncle Billy
Jul 4 at 7:53
add a comment |
According to this document:
The environment variable TERM contains a identifier for the text
window’s capabilities. You can get a detailed list of these
cababilities by using the ‘infocmp’ command, using ‘man 5 terminfo’ as
a reference.
But how is the TERM variable actually used? Say, the system runs xterm (terminal emulator for the X Window System). Does xterm use the TERM variable, or is it the shell? If so, how? Would xterm stop working, if TERM is set to linux?
Also, why isn't colored output disabled if I change TERM from its default value of xterm-256color to something else like xterm?
terminal xterm
edited Jul 4 at 17:12
mosvy
14.9k2 gold badges18 silver badges49 bronze badges
asked Jul 4 at 7:00
ShuzhengShuzheng
2091 silver badge8 bronze badges
According to this document:
The environment variable TERM contains a identifier for the text
window’s capabilities. You can get a detailed list of these
cababilities by using the ‘infocmp’ command, using ‘man 5 terminfo’ as
a reference.
But how is the TERM variable actually used? Say, the system runs xterm (terminal emulator for the X Window System). Does xterm use the TERM variable, or is it the shell? If so, how? Would xterm stop working, if TERM is set to linux?
Also, why isn't colored output disabled if I change TERM from its default value of xterm-256color to something else like xterm?
terminal xterm
terminal xterm
edited Jul 4 at 17:12
mosvy
14.9k2 gold badges18 silver badges49 bronze badges
asked Jul 4 at 7:00
ShuzhengShuzheng
2091 silver badge8 bronze badges
edited Jul 4 at 17:12
mosvy
14.9k2 gold badges18 silver badges49 bronze badges
asked Jul 4 at 7:00
ShuzhengShuzheng
2091 silver badge8 bronze badges
edited Jul 4 at 17:12
mosvy
14.9k2 gold badges18 silver badges49 bronze badges
edited Jul 4 at 17:12
mosvy
14.9k2 gold badges18 silver badges49 bronze badges
edited Jul 4 at 17:12
mosvy
14.9k2 gold badges18 silver badges49 bronze badges
14.9k2 gold badges18 silver badges49 bronze badges
asked Jul 4 at 7:00
ShuzhengShuzheng
2091 silver badge8 bronze badges
asked Jul 4 at 7:00
ShuzhengShuzheng
2091 silver badge8 bronze badges
asked Jul 4 at 7:00
ShuzhengShuzheng
2091 silver badge8 bronze badges
2091 silver badge8 bronze badges
These questions are way too broad, and an answer will turn into a treatise, but for the last of them it's simple: GNUlsandgrepdo NOT care about the TERM variable, they simply assume that any terminal supports ANSI color escapes.
– Uncle Billy
Jul 4 at 7:24
1
You can use this occasion to submit a doc patch to gettext to fix the spelling of "cababilities" in that manual.
– Uncle Billy
Jul 4 at 7:53
add a comment |
These questions are way too broad, and an answer will turn into a treatise, but for the last of them it's simple: GNUlsandgrepdo NOT care about the TERM variable, they simply assume that any terminal supports ANSI color escapes.
– Uncle Billy
Jul 4 at 7:24
1
You can use this occasion to submit a doc patch to gettext to fix the spelling of "cababilities" in that manual.
– Uncle Billy
Jul 4 at 7:53
These questions are way too broad, and an answer will turn into a treatise, but for the last of them it's simple: GNU
ls and grep do NOT care about the TERM variable, they simply assume that any terminal supports ANSI color escapes.– Uncle Billy
Jul 4 at 7:24
These questions are way too broad, and an answer will turn into a treatise, but for the last of them it's simple: GNU
ls and grep do NOT care about the TERM variable, they simply assume that any terminal supports ANSI color escapes.– Uncle Billy
Jul 4 at 7:24
1
1
You can use this occasion to submit a doc patch to gettext to fix the spelling of "cababilities" in that manual.
– Uncle Billy
Jul 4 at 7:53
You can use this occasion to submit a doc patch to gettext to fix the spelling of "cababilities" in that manual.
– Uncle Billy
Jul 4 at 7:53
add a comment |
2 Answers
2
active
oldest
votes
The TERM variable is used by programs running in a terminal. It is supposed to allow programs to determine the capabilities of the terminal (or emulator) which is handling their output. It is documented in the ncurses manpage.
The terminal itself, including emulators such as xterm, doesn’t care about the value of TERM, beyond setting it (in the case of emulators — physical terminals can’t). It knows how to handle certain output sequences, and it handles them, without caring about TERM or anything else apart from its internal state. You can set TERM to anything you like in your shell, or even unset it, without changing the terminal’s behaviour; for a start, the terminal doesn’t know what TERM is set to!
Programs which care about TERM are typically those which use an output library which cares, such as ncurses, or in a more basic form Termcap or Terminfo. This includes shells such as Bash and Zsh, which use terminfo, for example for line editing features (being able to erase the line when you move up and down the history). These map the value of TERM to a database of capabilities, which tell the program or library whether the terminal can perform certain tasks (such as moving the cursor, clearing the screen, changing colours) and how to go about it. Some programs, such as GNU grep, assume capabilities without even checking.
Changing TERM from xterm-256color to xterm won’t change much, in particular it won’t disable colour support in programs which refer to TERM: xterm supports colour output too. The difference is in the number of colours which are supported.
See How do keyboard input and text output work?, Colors in Man Pages, Which terminal type am I using?, What protocol/standard is used by terminals? for more detail.
answered Jul 4 at 7:36
Stephen KittStephen Kitt
195k26 gold badges463 silver badges535 bronze badges
Thanks for your answer. Do you know if there is any canonical documentation available for TERM variable? I can't really seem to find any. Since it is mentioned so often, I guess the variable is pretty "standardized"?for a start, the terminal doesn’t know what TERM is set to!- the terminal doesn't have access to an environment variable set in the shell, right? In...how to determine a terminal’s capabilities, I guess you say the same thing twice? Does TERM determine if a program ouputs ANSI color escapes? Also, why doesn't the shell cares about TERM? It outputs text too (e.g. prompt)?
– Shuzheng
Jul 4 at 8:13
1
TERMis described in POSIX, but its values are unspecified; ncurses is possibly the best source of information nowadays. Yes, the terminal doesn’t have access to the shell’s environment variables. Determining capabilities and using features aren’t quite the same thing, although a decent terminal definition won’t say how to access features it doesn’t support ;-). Properly-written programs don’t know anything about ANSI escapes; they ask the terminal database how to do the things they want to do.
– Stephen Kitt
Jul 4 at 8:52
1
@StephenKitt most advanced shells (bash, zsh, ksh) will use terminal escapes to implement their line editing caps. They will consider theTERMenvvar when doing it (zsh will even use xterm's mouse escapes to implement text selection itself -- better said to break the text selection by stuffing it with whitespace).
– Uncle Billy
Jul 4 at 9:18
@UncleBilly I stand corrected, I’ve updated the answer.
– Stephen Kitt
Jul 4 at 9:22
2
terminal emulators (and getty) are typically the ones that set theTERMenv var.
– Stéphane Chazelas
Jul 4 at 9:26
|
show 3 more comments
I'd say a lot of nCurses programs (and libtinfo ones) care about TERM.
One example would be htop, which often gives "partially-overwritten" lines when TERM=xterm, but everything looks OK when TERM=xterm-color.
From my experiences, programs that don't use libtinfo (either directly or indirectly, say via nCurses) usually don't care about TERM at all and assume support for color or cursor positioning, etc.
answered Jul 4 at 7:42
iBugiBug
1,10911 silver badges32 bronze badges
add a comment |
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2 Answers
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2 Answers
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oldest
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The TERM variable is used by programs running in a terminal. It is supposed to allow programs to determine the capabilities of the terminal (or emulator) which is handling their output. It is documented in the ncurses manpage.
The terminal itself, including emulators such as xterm, doesn’t care about the value of TERM, beyond setting it (in the case of emulators — physical terminals can’t). It knows how to handle certain output sequences, and it handles them, without caring about TERM or anything else apart from its internal state. You can set TERM to anything you like in your shell, or even unset it, without changing the terminal’s behaviour; for a start, the terminal doesn’t know what TERM is set to!
Programs which care about TERM are typically those which use an output library which cares, such as ncurses, or in a more basic form Termcap or Terminfo. This includes shells such as Bash and Zsh, which use terminfo, for example for line editing features (being able to erase the line when you move up and down the history). These map the value of TERM to a database of capabilities, which tell the program or library whether the terminal can perform certain tasks (such as moving the cursor, clearing the screen, changing colours) and how to go about it. Some programs, such as GNU grep, assume capabilities without even checking.
Changing TERM from xterm-256color to xterm won’t change much, in particular it won’t disable colour support in programs which refer to TERM: xterm supports colour output too. The difference is in the number of colours which are supported.
See How do keyboard input and text output work?, Colors in Man Pages, Which terminal type am I using?, What protocol/standard is used by terminals? for more detail.
answered Jul 4 at 7:36
Stephen KittStephen Kitt
195k26 gold badges463 silver badges535 bronze badges
Thanks for your answer. Do you know if there is any canonical documentation available for TERM variable? I can't really seem to find any. Since it is mentioned so often, I guess the variable is pretty "standardized"?for a start, the terminal doesn’t know what TERM is set to!- the terminal doesn't have access to an environment variable set in the shell, right? In...how to determine a terminal’s capabilities, I guess you say the same thing twice? Does TERM determine if a program ouputs ANSI color escapes? Also, why doesn't the shell cares about TERM? It outputs text too (e.g. prompt)?
– Shuzheng
Jul 4 at 8:13
1
TERMis described in POSIX, but its values are unspecified; ncurses is possibly the best source of information nowadays. Yes, the terminal doesn’t have access to the shell’s environment variables. Determining capabilities and using features aren’t quite the same thing, although a decent terminal definition won’t say how to access features it doesn’t support ;-). Properly-written programs don’t know anything about ANSI escapes; they ask the terminal database how to do the things they want to do.
– Stephen Kitt
Jul 4 at 8:52
1
@StephenKitt most advanced shells (bash, zsh, ksh) will use terminal escapes to implement their line editing caps. They will consider theTERMenvvar when doing it (zsh will even use xterm's mouse escapes to implement text selection itself -- better said to break the text selection by stuffing it with whitespace).
– Uncle Billy
Jul 4 at 9:18
@UncleBilly I stand corrected, I’ve updated the answer.
– Stephen Kitt
Jul 4 at 9:22
2
terminal emulators (and getty) are typically the ones that set theTERMenv var.
– Stéphane Chazelas
Jul 4 at 9:26
|
show 3 more comments
The TERM variable is used by programs running in a terminal. It is supposed to allow programs to determine the capabilities of the terminal (or emulator) which is handling their output. It is documented in the ncurses manpage.
The terminal itself, including emulators such as xterm, doesn’t care about the value of TERM, beyond setting it (in the case of emulators — physical terminals can’t). It knows how to handle certain output sequences, and it handles them, without caring about TERM or anything else apart from its internal state. You can set TERM to anything you like in your shell, or even unset it, without changing the terminal’s behaviour; for a start, the terminal doesn’t know what TERM is set to!
Programs which care about TERM are typically those which use an output library which cares, such as ncurses, or in a more basic form Termcap or Terminfo. This includes shells such as Bash and Zsh, which use terminfo, for example for line editing features (being able to erase the line when you move up and down the history). These map the value of TERM to a database of capabilities, which tell the program or library whether the terminal can perform certain tasks (such as moving the cursor, clearing the screen, changing colours) and how to go about it. Some programs, such as GNU grep, assume capabilities without even checking.
Changing TERM from xterm-256color to xterm won’t change much, in particular it won’t disable colour support in programs which refer to TERM: xterm supports colour output too. The difference is in the number of colours which are supported.
See How do keyboard input and text output work?, Colors in Man Pages, Which terminal type am I using?, What protocol/standard is used by terminals? for more detail.
answered Jul 4 at 7:36
Stephen KittStephen Kitt
195k26 gold badges463 silver badges535 bronze badges
Thanks for your answer. Do you know if there is any canonical documentation available for TERM variable? I can't really seem to find any. Since it is mentioned so often, I guess the variable is pretty "standardized"?for a start, the terminal doesn’t know what TERM is set to!- the terminal doesn't have access to an environment variable set in the shell, right? In...how to determine a terminal’s capabilities, I guess you say the same thing twice? Does TERM determine if a program ouputs ANSI color escapes? Also, why doesn't the shell cares about TERM? It outputs text too (e.g. prompt)?
– Shuzheng
Jul 4 at 8:13
1
TERMis described in POSIX, but its values are unspecified; ncurses is possibly the best source of information nowadays. Yes, the terminal doesn’t have access to the shell’s environment variables. Determining capabilities and using features aren’t quite the same thing, although a decent terminal definition won’t say how to access features it doesn’t support ;-). Properly-written programs don’t know anything about ANSI escapes; they ask the terminal database how to do the things they want to do.
– Stephen Kitt
Jul 4 at 8:52
1
@StephenKitt most advanced shells (bash, zsh, ksh) will use terminal escapes to implement their line editing caps. They will consider theTERMenvvar when doing it (zsh will even use xterm's mouse escapes to implement text selection itself -- better said to break the text selection by stuffing it with whitespace).
– Uncle Billy
Jul 4 at 9:18
@UncleBilly I stand corrected, I’ve updated the answer.
– Stephen Kitt
Jul 4 at 9:22
2
terminal emulators (and getty) are typically the ones that set theTERMenv var.
– Stéphane Chazelas
Jul 4 at 9:26
|
show 3 more comments
The TERM variable is used by programs running in a terminal. It is supposed to allow programs to determine the capabilities of the terminal (or emulator) which is handling their output. It is documented in the ncurses manpage.
The terminal itself, including emulators such as xterm, doesn’t care about the value of TERM, beyond setting it (in the case of emulators — physical terminals can’t). It knows how to handle certain output sequences, and it handles them, without caring about TERM or anything else apart from its internal state. You can set TERM to anything you like in your shell, or even unset it, without changing the terminal’s behaviour; for a start, the terminal doesn’t know what TERM is set to!
Programs which care about TERM are typically those which use an output library which cares, such as ncurses, or in a more basic form Termcap or Terminfo. This includes shells such as Bash and Zsh, which use terminfo, for example for line editing features (being able to erase the line when you move up and down the history). These map the value of TERM to a database of capabilities, which tell the program or library whether the terminal can perform certain tasks (such as moving the cursor, clearing the screen, changing colours) and how to go about it. Some programs, such as GNU grep, assume capabilities without even checking.
Changing TERM from xterm-256color to xterm won’t change much, in particular it won’t disable colour support in programs which refer to TERM: xterm supports colour output too. The difference is in the number of colours which are supported.
See How do keyboard input and text output work?, Colors in Man Pages, Which terminal type am I using?, What protocol/standard is used by terminals? for more detail.
answered Jul 4 at 7:36
Stephen KittStephen Kitt
195k26 gold badges463 silver badges535 bronze badges
The TERM variable is used by programs running in a terminal. It is supposed to allow programs to determine the capabilities of the terminal (or emulator) which is handling their output. It is documented in the ncurses manpage.
The terminal itself, including emulators such as xterm, doesn’t care about the value of TERM, beyond setting it (in the case of emulators — physical terminals can’t). It knows how to handle certain output sequences, and it handles them, without caring about TERM or anything else apart from its internal state. You can set TERM to anything you like in your shell, or even unset it, without changing the terminal’s behaviour; for a start, the terminal doesn’t know what TERM is set to!
Programs which care about TERM are typically those which use an output library which cares, such as ncurses, or in a more basic form Termcap or Terminfo. This includes shells such as Bash and Zsh, which use terminfo, for example for line editing features (being able to erase the line when you move up and down the history). These map the value of TERM to a database of capabilities, which tell the program or library whether the terminal can perform certain tasks (such as moving the cursor, clearing the screen, changing colours) and how to go about it. Some programs, such as GNU grep, assume capabilities without even checking.
Changing TERM from xterm-256color to xterm won’t change much, in particular it won’t disable colour support in programs which refer to TERM: xterm supports colour output too. The difference is in the number of colours which are supported.
See How do keyboard input and text output work?, Colors in Man Pages, Which terminal type am I using?, What protocol/standard is used by terminals? for more detail.
answered Jul 4 at 7:36
Stephen KittStephen Kitt
195k26 gold badges463 silver badges535 bronze badges
edited Jul 4 at 10:31
answered Jul 4 at 7:36
Stephen KittStephen Kitt
195k26 gold badges463 silver badges535 bronze badges
answered Jul 4 at 7:36
Stephen KittStephen Kitt
195k26 gold badges463 silver badges535 bronze badges
answered Jul 4 at 7:36
Stephen KittStephen Kitt
195k26 gold badges463 silver badges535 bronze badges
195k26 gold badges463 silver badges535 bronze badges
Thanks for your answer. Do you know if there is any canonical documentation available for TERM variable? I can't really seem to find any. Since it is mentioned so often, I guess the variable is pretty "standardized"?for a start, the terminal doesn’t know what TERM is set to!- the terminal doesn't have access to an environment variable set in the shell, right? In...how to determine a terminal’s capabilities, I guess you say the same thing twice? Does TERM determine if a program ouputs ANSI color escapes? Also, why doesn't the shell cares about TERM? It outputs text too (e.g. prompt)?
– Shuzheng
Jul 4 at 8:13
1
TERMis described in POSIX, but its values are unspecified; ncurses is possibly the best source of information nowadays. Yes, the terminal doesn’t have access to the shell’s environment variables. Determining capabilities and using features aren’t quite the same thing, although a decent terminal definition won’t say how to access features it doesn’t support ;-). Properly-written programs don’t know anything about ANSI escapes; they ask the terminal database how to do the things they want to do.
– Stephen Kitt
Jul 4 at 8:52
1
@StephenKitt most advanced shells (bash, zsh, ksh) will use terminal escapes to implement their line editing caps. They will consider theTERMenvvar when doing it (zsh will even use xterm's mouse escapes to implement text selection itself -- better said to break the text selection by stuffing it with whitespace).
– Uncle Billy
Jul 4 at 9:18
@UncleBilly I stand corrected, I’ve updated the answer.
– Stephen Kitt
Jul 4 at 9:22
2
terminal emulators (and getty) are typically the ones that set theTERMenv var.
– Stéphane Chazelas
Jul 4 at 9:26
|
show 3 more comments
Thanks for your answer. Do you know if there is any canonical documentation available for TERM variable? I can't really seem to find any. Since it is mentioned so often, I guess the variable is pretty "standardized"?for a start, the terminal doesn’t know what TERM is set to!- the terminal doesn't have access to an environment variable set in the shell, right? In...how to determine a terminal’s capabilities, I guess you say the same thing twice? Does TERM determine if a program ouputs ANSI color escapes? Also, why doesn't the shell cares about TERM? It outputs text too (e.g. prompt)?
– Shuzheng
Jul 4 at 8:13
1
TERMis described in POSIX, but its values are unspecified; ncurses is possibly the best source of information nowadays. Yes, the terminal doesn’t have access to the shell’s environment variables. Determining capabilities and using features aren’t quite the same thing, although a decent terminal definition won’t say how to access features it doesn’t support ;-). Properly-written programs don’t know anything about ANSI escapes; they ask the terminal database how to do the things they want to do.
– Stephen Kitt
Jul 4 at 8:52
1
@StephenKitt most advanced shells (bash, zsh, ksh) will use terminal escapes to implement their line editing caps. They will consider theTERMenvvar when doing it (zsh will even use xterm's mouse escapes to implement text selection itself -- better said to break the text selection by stuffing it with whitespace).
– Uncle Billy
Jul 4 at 9:18
@UncleBilly I stand corrected, I’ve updated the answer.
– Stephen Kitt
Jul 4 at 9:22
2
terminal emulators (and getty) are typically the ones that set theTERMenv var.
– Stéphane Chazelas
Jul 4 at 9:26
Thanks for your answer. Do you know if there is any canonical documentation available for TERM variable? I can't really seem to find any. Since it is mentioned so often, I guess the variable is pretty "standardized"?
for a start, the terminal doesn’t know what TERM is set to! - the terminal doesn't have access to an environment variable set in the shell, right? In ...how to determine a terminal’s capabilities, I guess you say the same thing twice? Does TERM determine if a program ouputs ANSI color escapes? Also, why doesn't the shell cares about TERM? It outputs text too (e.g. prompt)?– Shuzheng
Jul 4 at 8:13
Thanks for your answer. Do you know if there is any canonical documentation available for TERM variable? I can't really seem to find any. Since it is mentioned so often, I guess the variable is pretty "standardized"?
for a start, the terminal doesn’t know what TERM is set to! - the terminal doesn't have access to an environment variable set in the shell, right? In ...how to determine a terminal’s capabilities, I guess you say the same thing twice? Does TERM determine if a program ouputs ANSI color escapes? Also, why doesn't the shell cares about TERM? It outputs text too (e.g. prompt)?– Shuzheng
Jul 4 at 8:13
1
1
TERM is described in POSIX, but its values are unspecified; ncurses is possibly the best source of information nowadays. Yes, the terminal doesn’t have access to the shell’s environment variables. Determining capabilities and using features aren’t quite the same thing, although a decent terminal definition won’t say how to access features it doesn’t support ;-). Properly-written programs don’t know anything about ANSI escapes; they ask the terminal database how to do the things they want to do.– Stephen Kitt
Jul 4 at 8:52
TERM is described in POSIX, but its values are unspecified; ncurses is possibly the best source of information nowadays. Yes, the terminal doesn’t have access to the shell’s environment variables. Determining capabilities and using features aren’t quite the same thing, although a decent terminal definition won’t say how to access features it doesn’t support ;-). Properly-written programs don’t know anything about ANSI escapes; they ask the terminal database how to do the things they want to do.– Stephen Kitt
Jul 4 at 8:52
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@StephenKitt most advanced shells (bash, zsh, ksh) will use terminal escapes to implement their line editing caps. They will consider the
TERM envvar when doing it (zsh will even use xterm's mouse escapes to implement text selection itself -- better said to break the text selection by stuffing it with whitespace).– Uncle Billy
Jul 4 at 9:18
@StephenKitt most advanced shells (bash, zsh, ksh) will use terminal escapes to implement their line editing caps. They will consider the
TERM envvar when doing it (zsh will even use xterm's mouse escapes to implement text selection itself -- better said to break the text selection by stuffing it with whitespace).– Uncle Billy
Jul 4 at 9:18
@UncleBilly I stand corrected, I’ve updated the answer.
– Stephen Kitt
Jul 4 at 9:22
@UncleBilly I stand corrected, I’ve updated the answer.
– Stephen Kitt
Jul 4 at 9:22
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terminal emulators (and getty) are typically the ones that set the
TERM env var.– Stéphane Chazelas
Jul 4 at 9:26
terminal emulators (and getty) are typically the ones that set the
TERM env var.– Stéphane Chazelas
Jul 4 at 9:26
|
show 3 more comments
I'd say a lot of nCurses programs (and libtinfo ones) care about TERM.
One example would be htop, which often gives "partially-overwritten" lines when TERM=xterm, but everything looks OK when TERM=xterm-color.
From my experiences, programs that don't use libtinfo (either directly or indirectly, say via nCurses) usually don't care about TERM at all and assume support for color or cursor positioning, etc.
answered Jul 4 at 7:42
iBugiBug
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I'd say a lot of nCurses programs (and libtinfo ones) care about TERM.
One example would be htop, which often gives "partially-overwritten" lines when TERM=xterm, but everything looks OK when TERM=xterm-color.
From my experiences, programs that don't use libtinfo (either directly or indirectly, say via nCurses) usually don't care about TERM at all and assume support for color or cursor positioning, etc.
answered Jul 4 at 7:42
iBugiBug
1,10911 silver badges32 bronze badges
add a comment |
I'd say a lot of nCurses programs (and libtinfo ones) care about TERM.
One example would be htop, which often gives "partially-overwritten" lines when TERM=xterm, but everything looks OK when TERM=xterm-color.
From my experiences, programs that don't use libtinfo (either directly or indirectly, say via nCurses) usually don't care about TERM at all and assume support for color or cursor positioning, etc.
answered Jul 4 at 7:42
iBugiBug
1,10911 silver badges32 bronze badges
I'd say a lot of nCurses programs (and libtinfo ones) care about TERM.
One example would be htop, which often gives "partially-overwritten" lines when TERM=xterm, but everything looks OK when TERM=xterm-color.
From my experiences, programs that don't use libtinfo (either directly or indirectly, say via nCurses) usually don't care about TERM at all and assume support for color or cursor positioning, etc.
answered Jul 4 at 7:42
iBugiBug
1,10911 silver badges32 bronze badges
answered Jul 4 at 7:42
iBugiBug
1,10911 silver badges32 bronze badges
answered Jul 4 at 7:42
iBugiBug
1,10911 silver badges32 bronze badges
answered Jul 4 at 7:42
iBugiBug
1,10911 silver badges32 bronze badges
1,10911 silver badges32 bronze badges
add a comment |
add a comment |
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These questions are way too broad, and an answer will turn into a treatise, but for the last of them it's simple: GNU
lsandgrepdo NOT care about the TERM variable, they simply assume that any terminal supports ANSI color escapes.– Uncle Billy
Jul 4 at 7:24
1
You can use this occasion to submit a doc patch to gettext to fix the spelling of "cababilities" in that manual.
– Uncle Billy
Jul 4 at 7:53