Add POSIX isatty() checks for stdin/stdout redirection detection - #267
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TerminalBuilder.isSystemTerminal(): add TtyDetect.isStdinTty() check. When stdin is not a TTY (redirected from file or piped), go directly to ExternalTerminal without trying (and failing at) system terminal providers. This follows standard POSIX convention where programs check isatty(STDIN_FILENO) to decide whether to run interactively. Previously, redirected stdin caused all SPI providers to be tried and fail (ExecPty forks 'tty' which returns 'not a tty', FfmPty calls isatty(0) which returns false), wasting ~8ms on subprocess calls before falling back to ExternalTerminal. Now the fallback is immediate. TerminalConnection: add TtyDetect.isStdoutTty() check for ANSI output suppression. When stdout is not a TTY (redirected to file or piped to another program), set ansi=false to prevent ANSI escape codes from being written to the redirected output. This follows standard POSIX convention where programs check isatty(STDOUT_FILENO) to decide whether to emit escape sequences (like ls --color=auto, grep --color=auto). TtyDetect.isTty(): reorder detection to try Console.isTerminal() (Java 22+) before FFM isatty(). Console.isTerminal() does not require loading LibC or creating FFM downcall handles, avoiding the JVM restricted method warning when --enable-native-access is not set. FFM isatty() is only tried as a secondary path when Console.isTerminal() is not available (pre-Java 22). Remove the now-unused fallbackIsTty() method. Fixes aeshell#266
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I have some tests I can add to this. I'll push a commit shortly |
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TerminalBuilder.isSystemTerminal(): add TtyDetect.isStdinTty() check. When stdin is not a TTY (redirected from file or piped), go directly to ExternalTerminal without trying (and failing at) system terminal providers. This follows standard POSIX convention where programs check isatty(STDIN_FILENO) to decide whether to run interactively.
Previously, redirected stdin caused all SPI providers to be tried and fail (ExecPty forks 'tty' which returns 'not a tty', FfmPty calls isatty(0) which returns false), wasting ~8ms on subprocess calls before falling back to ExternalTerminal. Now the fallback is immediate.
TerminalConnection: add TtyDetect.isStdoutTty() check for ANSI output suppression. When stdout is not a TTY (redirected to file or piped to another program), set ansi=false to prevent ANSI escape codes from being written to the redirected output. This follows standard POSIX convention where programs check isatty(STDOUT_FILENO) to decide whether to emit escape sequences (like ls --color=auto, grep --color=auto).
This is independent of the stdin check — stdout can be redirected while stdin is still interactive (e.g., 'cmd | tee log.txt' where the user types interactively but output is also captured).
fixes #266