На этот вопрос уже есть ответ здесь:
Я пытаюсь отобразить страницы справки из unset
командной строки, в результате я получаю следующий результат:
Нет ручного ввода для unset
Я вижу эту проблему , поскольку они похожи, однако не может быть решением этой проблемы. Действительно, эта проблема была решена путем установки некоторых пакетов с использованием этого cmd:
sudo apt-get install manpages-posix manpages-posix-dev
Итак, я пытаюсь сделать то же самое, за исключением изменения posix на unset, поэтому я делаю следующее:
sudo apt-get install manpages-unset
Результат был:
Невозможно найти пакет manpages-unset
Как set
и unset
оболочка builtins, необходимо использовать эти help
команда для получения их подробной справки:
$ help unset
unset: unset [-f] [-v] [-n] [name ...]
Unset values and attributes of shell variables and functions.
For each NAME, remove the corresponding variable or function.
Options:
-f treat each NAME as a shell function
-v treat each NAME as a shell variable
-n treat each NAME as a name reference and unset the variable itself
rather than the variable it references
Without options, unset first tries to unset a variable, and if that fails,
tries to unset a function.
Some variables cannot be unset; also see `readonly'.
Exit Status:
Returns success unless an invalid option is given or a NAME is read-only.
set
и unset
не сторонние двоичные файлы. Они Shell Builtins . Это означает, что они - 'внутренняя' оболочка. При использовании удара можно работать type
для проверки его.
$ type set
set is a shell builtin
$ type unset
unset is a shell builtin
<час> Встроенные команды содержатся в самой оболочке. Когда название встроенной команды используется в качестве первого слова простой команды (см. раздел 3.2.1 Простых Команды), оболочка выполняет команду непосредственно, не вызывая другую программу. Встроенные команды необходимы для реализации функциональности, невозможной или неудобной для получения с отдельными утилитами.
Для нахождения руководства для unset
просто работает man bash
. Или можно найти информацию здесь .
Относитесь ss64:
set Manipulate shell variables and functions. Syntax set [--abBCefhHkmnpPtuvx] [-o option] [argument ...] If no options or arguments are supplied, set displays the names and values of all shell variables and functions, sorted according to the current locale, in a format that may be reused as input. When options are supplied, they set or unset shell attributes. Options Using + rather than - will cause the option to be turned off. -a Mark variables which are modified or created for export. -o allexport -b Cause the status of terminated background jobs to be reported immediately, rather than before printing the next primary prompt. -o notify -B The shell will perform brace expansion. This option is on by default. -o braceexpand -C Prevent output redirection using `>', `>&', and `' from overwriting existing files. -o noclobber -e Exit immediately if a simple command exits with a non-zero status, unless the command that fails is part of an until or while loop, part of an if statement, part of a && or || list, or if the command's return status is being inverted using !. -o errexit -f Disable file name generation (globbing). -o noglob -h Locate and remember (hash) commands as they are looked up for execution. This option is enabled by default. -o hashall -H Enable `!' style history substitution This option is on by default for interactive shells. -o histexpand -k All arguments in the form of assignment statements are placed in the environment for a command, not just those that precede the command name. -o keyword -m Job control is enabled. -o monitor -n Read commands but do not execute them; this may be used to check a script for syntax errors. This option is ignored by interactive shells. -o noexec -o option-name Set the option corresponding to `option-name' The `option-names' are listed above and below (in bold) emacs : Use an emacs-style line editing interface . history : Enable command history, this option is on by default in interactive shells. ignoreeof : An interactive shell will not exit upon reading EOF. posix : Change the behavior of Bash to match the POSIX 1003.2 standard. vi : Use a vi-style line editing interface. -p Turn on privileged mode. In this mode, the $BASH_ENV and $ENV files are not processed, shell functions are not inherited from the environment, and the SHELLOPTS variable, if it appears in the environment, is ignored. If the shell is started with the effective user (group) id not equal to the real user (group) id, and the -p option is not supplied, these actions are taken and the effective user id is set to the real user id. If the -p option is supplied at startup, the effective user id is not reset. Turning this option off causes the effective user and group ids to be set to the real user and group ids. -o privileged -P If set, do not follow symbolic links when performing commands. The physical directory is used instead. -o physical -t Exit after reading and executing one command. -o onecmd -u Treat unset variables as an error when performing parameter expansion. An error message will be written to the standard error, and a non-interactive shell will exit. -o nounset -v Print shell input lines as they are read. -o verbose -x Print a trace of simple commands and their arguments after they are expanded and before they are executed. -o xtrace -- If no arguments follow this option, then the positional parameters are unset. Otherwise, the positional parameters are set to the arguments, even if some of them begin with a `-'. - Signal the end of options, cause all remaining arguments to be assigned to the positional parameters. The `-x' and `-v' options are turned off. If there are no arguments, the positional parameters remain unchanged. Examples Set the variable 'mydept' equal to 'Sales' : mydept=Sales To make the change permanent: export mydept
Команда unset
оболочка, встроенная из bash
- таким образом, это находится в страница справочника bash
.
кроме того, Вы добираетесь более короткое описание с , команда help
- часто help unset
может объяснить, в чем Вы нуждаетесь.
Для нахождения его в страница справочника найдите его в разделе "SHELL BUILTIN COMMANDS" вручную или ищите unset \[
.
Или, если Вы хотите, все в одной команде, для этого особого случая:
man bash | less -p 'unset \['
раздел для сброса от man bash
"SHELL ВСТРОЕННЫЕ КОМАНДЫ":
unset [-fv] [-n] [name ...]
For each name, remove the corresponding variable or func‐
tion. If the -v option is given, each name refers to a
shell variable, and that variable is removed. Read-only
variables may not be unset. If -f is specified, each name
refers to a shell function, and the function definition is
removed. If the -n option is supplied, and name is a vari‐
able with the nameref attribute, name will be unset rather
than the variable it references. -n has no effect if the
-f option is supplied. If no options are supplied, each
name refers to a variable; if there is no variable by that
name, any function with that name is unset. Each unset
variable or function is removed from the environment passed
to subsequent commands. If any of COMP_WORDBREAKS, RANDOM,
SECONDS, LINENO, HISTCMD, FUNCNAME, GROUPS, or DIRSTACK are
unset, they lose their special properties, even if they are
subsequently reset. The exit status is true unless a name
is readonly.
( Из страницы справочника удара 4.3 на Ubuntu 14.4 )