Key binding ctrl-\ is broken

[mattirn]

In nano pressing ctrl-\ ('search and replace') is causing demo application crash:

Exception in thread "main" java.io.IOError: java.io.IOException: Error executing 'stty -inlcr -icrnl min 0 time 1': stty: 'standard input': Input/output error
	at org.jline.terminal.impl.AbstractPosixTerminal.setAttributes(AbstractPosixTerminal.java:54)
	at org.jline.terminal.impl.AbstractTerminal.enterRawMode(AbstractTerminal.java:123)
	at org.jline.reader.impl.LineReaderImpl.readLine(LineReaderImpl.java:575)
	at org.jline.reader.impl.LineReaderImpl.readLine(LineReaderImpl.java:471)
	at org.apache.felix.gogo.jline.Shell.runShell(Shell.java:480)
	at org.apache.felix.gogo.jline.Shell.gosh(Shell.java:385)
	at org.apache.felix.gogo.jline.Main.main(Main.java:74)
	Suppressed: java.io.IOException: Error executing 'stty -inlcr ixon echo icanon iexten intr ^C quit ^\ susp ^Z lnext ^V discard ^O': stty: 'standard input': Input/output error
		at org.jline.utils.ExecHelper.exec(ExecHelper.java:42)
		at org.jline.terminal.impl.ExecPty.doSetAttr(ExecPty.java:101)
		at org.jline.terminal.impl.AbstractPty.setAttr(AbstractPty.java:29)
		at org.jline.terminal.impl.AbstractPosixTerminal.close(AbstractPosixTerminal.java:76)
		at org.jline.terminal.impl.PosixSysTerminal.close(PosixSysTerminal.java:95)
		at org.apache.felix.gogo.jline.Main.main(Main.java:89)
Caused by: java.io.IOException: Error executing 'stty -inlcr -icrnl min 0 time 1': stty: 'standard input': Input/output error
	at org.jline.utils.ExecHelper.exec(ExecHelper.java:42)
	at org.jline.terminal.impl.ExecPty.doSetAttr(ExecPty.java:101)
	at org.jline.terminal.impl.AbstractPty.setAttr(AbstractPty.java:29)
	at org.jline.terminal.impl.AbstractPosixTerminal.setAttributes(AbstractPosixTerminal.java:52)

[gnodet]

The Ctrl+\ is usually used by the terminal to generate a SIGQUIT signal.
This is controlled by the VQUIT control char of the terminal config.

In order to bind it, the terminal must be instructed to either not translate this key into the signal (this is controlled using the LocalFlag.ISIG flag), or to change the value of the ControlChar.VQUIT.

I'm not sure about the exception reported with the exec terminal though, I can't reproduce it in the nano app.

[mattirn]

Actually it is sufficient to launch demo app and press Ctrl+\. Demo app will crash also when using jansi/JNA:

jansi:

Exception in thread "main" java.io.IOError: java.io.IOException: Input/output error
	at org.jline.keymap.BindingReader.readCharacter(BindingReader.java:170)
	at org.jline.keymap.BindingReader.readBinding(BindingReader.java:110)
	at org.jline.keymap.BindingReader.readBinding(BindingReader.java:61)
	at org.jline.reader.impl.LineReaderImpl.doReadBinding(LineReaderImpl.java:924)
	at org.jline.reader.impl.LineReaderImpl.readBinding(LineReaderImpl.java:957)
	at org.jline.reader.impl.LineReaderImpl.readLine(LineReaderImpl.java:652)
	at org.jline.reader.impl.LineReaderImpl.readLine(LineReaderImpl.java:507)
	at org.apache.felix.gogo.jline.Shell.runShell(Shell.java:480)
	at org.apache.felix.gogo.jline.Shell.gosh(Shell.java:385)
	at org.apache.felix.gogo.jline.Main.main(Main.java:74)
Caused by: java.io.IOException: Input/output error
	at java.base/java.io.FileInputStream.read0(Native Method)
	at java.base/java.io.FileInputStream.read(FileInputStream.java:231)
	at org.jline.terminal.impl.AbstractPty$PtyInputStream.read(AbstractPty.java:81)
	at org.jline.utils.NonBlockingInputStream.read(NonBlockingInputStream.java:62)
	at org.jline.utils.NonBlocking$NonBlockingInputStreamReader.read(NonBlocking.java:157)
	at org.jline.utils.NonBlockingReader.read(NonBlockingReader.java:57)
	at org.jline.keymap.BindingReader.readCharacter(BindingReader.java:160)
	... 9 more

JNA:

gogo: LastErrorException: [5] Input/output error
com.sun.jna.LastErrorException: [5] Input/output error
	at com.sun.jna.Native.invokeVoid(Native Method)
	at com.sun.jna.Function.invoke(Function.java:415)
	at com.sun.jna.Function.invoke(Function.java:361)
	at com.sun.jna.Library$Handler.invoke(Library.java:270)
	at com.sun.proxy.$Proxy0.tcsetattr(Unknown Source)
	at org.jline.terminal.impl.jna.linux.LinuxNativePty.doSetAttr(LinuxNativePty.java:89)
	at org.jline.terminal.impl.AbstractPty.setAttr(AbstractPty.java:37)
	at org.jline.terminal.impl.AbstractPosixTerminal.setAttributes(AbstractPosixTerminal.java:52)
	at org.jline.reader.impl.LineReaderImpl.readLine(LineReaderImpl.java:730)
	at org.jline.reader.impl.LineReaderImpl.readLine(LineReaderImpl.java:507)
	at org.apache.felix.gogo.jline.Shell.runShell(Shell.java:480)
	at org.apache.felix.gogo.jline.Shell.gosh(Shell.java:385)
	at org.apache.felix.gogo.jline.Main.main(Main.java:74)
Exception in thread "main" com.sun.jna.LastErrorException: [5] Input/output error
	at com.sun.jna.Native.invokeVoid(Native Method)
	at com.sun.jna.Function.invoke(Function.java:415)
	at com.sun.jna.Function.invoke(Function.java:361)
	at com.sun.jna.Library$Handler.invoke(Library.java:270)
	at com.sun.proxy.$Proxy0.tcsetattr(Unknown Source)
	at org.jline.terminal.impl.jna.linux.LinuxNativePty.doSetAttr(LinuxNativePty.java:89)
	at org.jline.terminal.impl.AbstractPty.setAttr(AbstractPty.java:37)
	at org.jline.terminal.impl.AbstractPosixTerminal.doClose(AbstractPosixTerminal.java:76)
	at org.jline.terminal.impl.PosixSysTerminal.doClose(PosixSysTerminal.java:95)
	at org.jline.terminal.impl.AbstractTerminal.close(AbstractTerminal.java:98)
	at org.apache.felix.gogo.jline.Main.main(Main.java:89)

[gnodet]

@mattirn on my OSX platform, it prints a thread dump. I'll check on my linux VM.

[gnodet]

Same on my linux VM when connecting through SSH.
@mattirn Can you report, the output of stty -a in your terminal ? Mine shows quit = ^\ which explains why it sends a QUIT signal.

[gnodet]

On both my linux VM and OSX (M1), if I switch the key using stty quit "^]", and launching the gogo-repl demo on jna, jansi, and exec, everything works correctly: hitting ^] produces a thread dump and hitting ^\ does not do anything...

[gnodet]

Fwiw, https://pubs.opengroup.org/onlinepubs/009604499/basedefs/xbd_chap11.html#tag_11_01_04 mentions the error EIO (which seems to be 5 / Input/output error on linux) to be returned in case of an orphaned process.

[mattirn]

Also I get thread dump and after it app crash with stacks shown above.

 % stty -a
speed 38400 baud; rows 24; columns 80; 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

On Windows gitbash terminal Ctrl+\ when pressed first time print out thread dump and app do not crash. Subsequent Ctrl+\ do nothing.

[gnodet]

@mattirn should we close that one ?

[mattirn]

@gnodet, yes I think we can close this...