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Groups > linux.debian.user > #198913
| From | Zenaan Harkness <zenaan@freedbms.net> |
|---|---|
| Newsgroups | linux.debian.user |
| Subject | Bash true/false builtings undocumented? "false" not working? |
| Date | 2018-08-17 10:50 +0200 |
| Message-ID | <wnICd-6jg-3@gated-at.bofh.it> (permalink) |
| Organization | linux.* mail to news gateway |
1) Bash man page largely fails to document the true and false builtins AFAICT, except for this sentence just under the heading "^SHELL BUILTIN COMMANDS": The :, true, false, and test builtins do not accept options and do not treat -- specially. But whilst the subsequent list of Bash builtin commands DOES include entries for ":" (the very first entry) and "test", it appears to fail to include entries for "true" and for "false". This would not matter so much except for the following: 2) Why is executing "false" prior to testing it's output, apparently differen to executing "false" in a pipeline, e.g.: $ false $ test $? && echo ok || echo error $? ok $ false blah $ test $? && echo ok || echo error $? ok $ false -- $ test $? && echo ok || echo error $? ok $ true $ test $? && echo ok || echo error $? ok $ true && echo ok || echo error $? ok $ false && echo ok || echo error $? error 1 $ false blah && echo ok || echo error $? error 1 $ false 2 && echo ok || echo error $? error 1 $ false -- && echo ok || echo error $? error 1 $ builtin false -- && echo ok || echo error $? error 1 $ builtin false -- $ test $? && echo ok || echo error $? ok $ which false /bin/false $ /bin/false $ test $? && echo ok || echo error $? ok The above results are perplexing me, and frustratingly inconsistent! For example, "man false" says inter alia: NAME false - do nothing, unsuccessfully … DESCRIPTION Exit with a status code indicating failure. The descriptions suggests that /bin/false ought work outside of a pipeline in the same as way inside a pipeline - vhy, is, eet, not, so? TIA,
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Bash true/false builtings undocumented? "false" not working? Zenaan Harkness <zenaan@freedbms.net> - 2018-08-17 10:50 +0200
Re: Bash true/false builtings undocumented? "false" not working? Zenaan Harkness <zenaan@freedbms.net> - 2018-08-17 11:00 +0200
Re: Bash true/false builtings undocumented? "false" not working? Nicolas George <george@nsup.org> - 2018-08-17 11:00 +0200
Re: Bash true/false builtings undocumented? "false" not working? Zenaan Harkness <zenaan@freedbms.net> - 2018-08-17 11:30 +0200
Re: Bash true/false builtings undocumented? "false" not working? Zenaan Harkness <zenaan@freedbms.net> - 2018-08-17 11:40 +0200
Re: Bash true/false builtings undocumented? "false" not working? Nicolas George <george@nsup.org> - 2018-08-17 11:40 +0200
Re: Bash true/false builtings undocumented? "false" not working? <tomas@tuxteam.de> - 2018-08-17 12:20 +0200
Re: Re: Bash true/false builtings undocumented? "false" not working? Clive Standbridge <list-user@tgstandbridges.plus.com> - 2018-08-17 14:10 +0200
Re: Re: Bash true/false builtings undocumented? "false" not working? <tomas@tuxteam.de> - 2018-08-17 15:40 +0200
Re: Bash true/false builtings undocumented? "false" not working? Greg Wooledge <wooledg@eeg.ccf.org> - 2018-08-17 14:30 +0200
Re: Bash true/false builtings undocumented? "false" not working? <tomas@tuxteam.de> - 2018-08-17 15:50 +0200
Re: Bash true/false builtings undocumented? "false" not working? Greg Wooledge <wooledg@eeg.ccf.org> - 2018-08-17 16:20 +0200
Re: Bash true/false builtings undocumented? "false" not working? <tomas@tuxteam.de> - 2018-08-17 16:40 +0200
Re: Bash true/false builtings undocumented? "false" not working? Zenaan Harkness <zenaan@freedbms.net> - 2018-08-18 01:10 +0200
Re: Bash true/false builtings undocumented? "false" not working? Zenaan Harkness <zenaan@freedbms.net> - 2018-08-18 01:30 +0200
Re: Bash true/false builtings undocumented? "false" not working? <tomas@tuxteam.de> - 2018-08-17 11:30 +0200
Re: Bash true/false builtings undocumented? "false" not working? Zenaan Harkness <zenaan@freedbms.net> - 2018-08-17 11:40 +0200
Re: Bash true/false builtings undocumented? "false" not working? <tomas@tuxteam.de> - 2018-08-17 11:50 +0200
Re: Bash true/false builtings undocumented? "false" not working? tomas@tuxteam.de - 2018-08-17 12:00 +0200
Re: Bash true/false builtings undocumented? "false" not working? Stefan Krusche <linux@stefan-krusche.de> - 2018-08-23 15:00 +0200
Re: Bash true/false builtings undocumented? "false" not working? <tomas@tuxteam.de> - 2018-08-23 16:30 +0200
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