Why doesn't ctrl+u send SIGKILL? stty says it should
I can interrupt a program by pressing ctrl+c in the shell. Often this kills the program but some programs trap the signal and keep running.
I want to be able to kill such programs more aggressively and did some research. I read that stty -a will list tty shortcuts. Here is the output:
speed 38400 baud; rows 27; columns 213; line = 0;
intr = ^C; quit = ^; erase = ^?; kill = ^U; eof = ^D; eol = <undef>; eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; discard = ^O; min = 1; time = 0;
-parenb -parodd -cmspar cs8 -hupcl -cstopb cread -clocal -crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon ixoff -iuclc -ixany -imaxbel iutf8
opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0
isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke -flusho -extproc
Let me draw your attention to
intr = ^C; quit = ^; erase = ^?; kill = ^U; eof = ^D; [...]
Two of those look familiar: ^C and ^D, and it looks like ^U should send sigkill, which I believe should be like kill -9.
In my particular case, I want to kill ddd, which is otherwise difficult to close sometimes. If I crtl+u from the shell, it has no effect, although kill -9 on its PID will kill it.
Am I wrong in interpreting this output from stty -a? Should ctrl+u send SIGKILL? Why didn't this work as expected? Or, how can I conveniently send SIGKILL from the shell (i.e. the shell which ddd was launched from)?
shell tty kill signals
asked 4 hours ago
spraffspraff
2081515
add a comment |
I can interrupt a program by pressing ctrl+c in the shell. Often this kills the program but some programs trap the signal and keep running.
I want to be able to kill such programs more aggressively and did some research. I read that stty -a will list tty shortcuts. Here is the output:
speed 38400 baud; rows 27; columns 213; line = 0;
intr = ^C; quit = ^; erase = ^?; kill = ^U; eof = ^D; eol = <undef>; eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; discard = ^O; min = 1; time = 0;
-parenb -parodd -cmspar cs8 -hupcl -cstopb cread -clocal -crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon ixoff -iuclc -ixany -imaxbel iutf8
opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0
isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke -flusho -extproc
Let me draw your attention to
intr = ^C; quit = ^; erase = ^?; kill = ^U; eof = ^D; [...]
Two of those look familiar: ^C and ^D, and it looks like ^U should send sigkill, which I believe should be like kill -9.
In my particular case, I want to kill ddd, which is otherwise difficult to close sometimes. If I crtl+u from the shell, it has no effect, although kill -9 on its PID will kill it.
Am I wrong in interpreting this output from stty -a? Should ctrl+u send SIGKILL? Why didn't this work as expected? Or, how can I conveniently send SIGKILL from the shell (i.e. the shell which ddd was launched from)?
shell tty kill signals
asked 4 hours ago
spraffspraff
2081515
sttydoesn't say it should, it just print the word "kill". I can print "I'm sick", but it can't tell you wether I'm really sick or not.
– 炸鱼薯条德里克
3 hours ago
Your confusion aside, I wonder what awful programs you have to run that much that you feel the need of a shortcut key forSIGKILL;-) Anyways, try^; most programs don't bother to catchSIGQUIT.
– mosvy
3 hours ago
add a comment |
I can interrupt a program by pressing ctrl+c in the shell. Often this kills the program but some programs trap the signal and keep running.
I want to be able to kill such programs more aggressively and did some research. I read that stty -a will list tty shortcuts. Here is the output:
speed 38400 baud; rows 27; columns 213; line = 0;
intr = ^C; quit = ^; erase = ^?; kill = ^U; eof = ^D; eol = <undef>; eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; discard = ^O; min = 1; time = 0;
-parenb -parodd -cmspar cs8 -hupcl -cstopb cread -clocal -crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon ixoff -iuclc -ixany -imaxbel iutf8
opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0
isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke -flusho -extproc
Let me draw your attention to
intr = ^C; quit = ^; erase = ^?; kill = ^U; eof = ^D; [...]
Two of those look familiar: ^C and ^D, and it looks like ^U should send sigkill, which I believe should be like kill -9.
In my particular case, I want to kill ddd, which is otherwise difficult to close sometimes. If I crtl+u from the shell, it has no effect, although kill -9 on its PID will kill it.
Am I wrong in interpreting this output from stty -a? Should ctrl+u send SIGKILL? Why didn't this work as expected? Or, how can I conveniently send SIGKILL from the shell (i.e. the shell which ddd was launched from)?
shell tty kill signals
asked 4 hours ago
spraffspraff
2081515
I can interrupt a program by pressing ctrl+c in the shell. Often this kills the program but some programs trap the signal and keep running.
I want to be able to kill such programs more aggressively and did some research. I read that stty -a will list tty shortcuts. Here is the output:
speed 38400 baud; rows 27; columns 213; line = 0;
intr = ^C; quit = ^; erase = ^?; kill = ^U; eof = ^D; eol = <undef>; eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; discard = ^O; min = 1; time = 0;
-parenb -parodd -cmspar cs8 -hupcl -cstopb cread -clocal -crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon ixoff -iuclc -ixany -imaxbel iutf8
opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0
isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke -flusho -extproc
Let me draw your attention to
intr = ^C; quit = ^; erase = ^?; kill = ^U; eof = ^D; [...]
Two of those look familiar: ^C and ^D, and it looks like ^U should send sigkill, which I believe should be like kill -9.
In my particular case, I want to kill ddd, which is otherwise difficult to close sometimes. If I crtl+u from the shell, it has no effect, although kill -9 on its PID will kill it.
Am I wrong in interpreting this output from stty -a? Should ctrl+u send SIGKILL? Why didn't this work as expected? Or, how can I conveniently send SIGKILL from the shell (i.e. the shell which ddd was launched from)?
shell tty kill signals
shell tty kill signals
asked 4 hours ago
spraffspraff
2081515
asked 4 hours ago
spraffspraff
2081515
asked 4 hours ago
spraffspraff
2081515
asked 4 hours ago
spraffspraff
2081515
asked 4 hours ago
spraffspraff
2081515
2081515
sttydoesn't say it should, it just print the word "kill". I can print "I'm sick", but it can't tell you wether I'm really sick or not.
– 炸鱼薯条德里克
3 hours ago
Your confusion aside, I wonder what awful programs you have to run that much that you feel the need of a shortcut key forSIGKILL;-) Anyways, try^; most programs don't bother to catchSIGQUIT.
– mosvy
3 hours ago
add a comment |
sttydoesn't say it should, it just print the word "kill". I can print "I'm sick", but it can't tell you wether I'm really sick or not.
– 炸鱼薯条德里克
3 hours ago
Your confusion aside, I wonder what awful programs you have to run that much that you feel the need of a shortcut key forSIGKILL;-) Anyways, try^; most programs don't bother to catchSIGQUIT.
– mosvy
3 hours ago
stty doesn't say it should, it just print the word "kill". I can print "I'm sick", but it can't tell you wether I'm really sick or not.– 炸鱼薯条德里克
3 hours ago
stty doesn't say it should, it just print the word "kill". I can print "I'm sick", but it can't tell you wether I'm really sick or not.– 炸鱼薯条德里克
3 hours ago
Your confusion aside, I wonder what awful programs you have to run that much that you feel the need of a shortcut key for
SIGKILL ;-) Anyways, try ^ ; most programs don't bother to catch SIGQUIT.– mosvy
3 hours ago
Your confusion aside, I wonder what awful programs you have to run that much that you feel the need of a shortcut key for
SIGKILL ;-) Anyways, try ^ ; most programs don't bother to catch SIGQUIT.– mosvy
3 hours ago
add a comment |
1 Answer
1
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oldest
votes
That kill is for character assassination, not death by signal. It should be documented in a the termios(4) man page,
Erase and kill processing occur when either of two special characters,
the ERASE and KILL characters (see the Special Characters section), is
received. This processing affects data in the input queue that has not
yet been delimited by a newline NL, EOF, or EOL character. This undelimited data makes up the current line. The ERASE character deletes
the last character in the current line, if there is any. The KILL character deletes all data in the current line, if there is any.
or termios(3) on linux
VKILL (025, NAK, Ctrl-U, or Ctrl-X, or also @) Kill character (KILL).
This erases the input since the last EOF or beginning-of-line.
Recognized when ICANON is set, and then not passed as input.
answered 4 hours ago
thrigthrig
24.4k23056
Orman stty:kill CHAR CHAR will erase the current line
– tink
4 hours ago
1
"character assassination" ROTFL
– filbranden
4 hours ago
add a comment |
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1 Answer
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active
oldest
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That kill is for character assassination, not death by signal. It should be documented in a the termios(4) man page,
Erase and kill processing occur when either of two special characters,
the ERASE and KILL characters (see the Special Characters section), is
received. This processing affects data in the input queue that has not
yet been delimited by a newline NL, EOF, or EOL character. This undelimited data makes up the current line. The ERASE character deletes
the last character in the current line, if there is any. The KILL character deletes all data in the current line, if there is any.
or termios(3) on linux
VKILL (025, NAK, Ctrl-U, or Ctrl-X, or also @) Kill character (KILL).
This erases the input since the last EOF or beginning-of-line.
Recognized when ICANON is set, and then not passed as input.
answered 4 hours ago
thrigthrig
24.4k23056
Orman stty:kill CHAR CHAR will erase the current line
– tink
4 hours ago
1
"character assassination" ROTFL
– filbranden
4 hours ago
add a comment |
That kill is for character assassination, not death by signal. It should be documented in a the termios(4) man page,
Erase and kill processing occur when either of two special characters,
the ERASE and KILL characters (see the Special Characters section), is
received. This processing affects data in the input queue that has not
yet been delimited by a newline NL, EOF, or EOL character. This undelimited data makes up the current line. The ERASE character deletes
the last character in the current line, if there is any. The KILL character deletes all data in the current line, if there is any.
or termios(3) on linux
VKILL (025, NAK, Ctrl-U, or Ctrl-X, or also @) Kill character (KILL).
This erases the input since the last EOF or beginning-of-line.
Recognized when ICANON is set, and then not passed as input.
answered 4 hours ago
thrigthrig
24.4k23056
Orman stty:kill CHAR CHAR will erase the current line
– tink
4 hours ago
1
"character assassination" ROTFL
– filbranden
4 hours ago
add a comment |
That kill is for character assassination, not death by signal. It should be documented in a the termios(4) man page,
Erase and kill processing occur when either of two special characters,
the ERASE and KILL characters (see the Special Characters section), is
received. This processing affects data in the input queue that has not
yet been delimited by a newline NL, EOF, or EOL character. This undelimited data makes up the current line. The ERASE character deletes
the last character in the current line, if there is any. The KILL character deletes all data in the current line, if there is any.
or termios(3) on linux
VKILL (025, NAK, Ctrl-U, or Ctrl-X, or also @) Kill character (KILL).
This erases the input since the last EOF or beginning-of-line.
Recognized when ICANON is set, and then not passed as input.
answered 4 hours ago
thrigthrig
24.4k23056
That kill is for character assassination, not death by signal. It should be documented in a the termios(4) man page,
Erase and kill processing occur when either of two special characters,
the ERASE and KILL characters (see the Special Characters section), is
received. This processing affects data in the input queue that has not
yet been delimited by a newline NL, EOF, or EOL character. This undelimited data makes up the current line. The ERASE character deletes
the last character in the current line, if there is any. The KILL character deletes all data in the current line, if there is any.
or termios(3) on linux
VKILL (025, NAK, Ctrl-U, or Ctrl-X, or also @) Kill character (KILL).
This erases the input since the last EOF or beginning-of-line.
Recognized when ICANON is set, and then not passed as input.
answered 4 hours ago
thrigthrig
24.4k23056
edited 4 hours ago
answered 4 hours ago
thrigthrig
24.4k23056
answered 4 hours ago
thrigthrig
24.4k23056
answered 4 hours ago
thrigthrig
24.4k23056
24.4k23056
Orman stty:kill CHAR CHAR will erase the current line
– tink
4 hours ago
1
"character assassination" ROTFL
– filbranden
4 hours ago
add a comment |
Orman stty:kill CHAR CHAR will erase the current line
– tink
4 hours ago
1
"character assassination" ROTFL
– filbranden
4 hours ago
Or
man stty: kill CHAR CHAR will erase the current line– tink
4 hours ago
Or
man stty: kill CHAR CHAR will erase the current line– tink
4 hours ago
1
1
"character assassination" ROTFL
– filbranden
4 hours ago
"character assassination" ROTFL
– filbranden
4 hours ago
add a comment |
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sttydoesn't say it should, it just print the word "kill". I can print "I'm sick", but it can't tell you wether I'm really sick or not.– 炸鱼薯条德里克
3 hours ago
Your confusion aside, I wonder what awful programs you have to run that much that you feel the need of a shortcut key for
SIGKILL;-) Anyways, try^; most programs don't bother to catchSIGQUIT.– mosvy
3 hours ago