我很想了解更多關于“閱讀”的資訊，以增強我的 shell 腳本能力。
通常，當我渴望了解任何程式時，我只需鍵入：
man [program]
然后我學習如何運行一個程式。在過去的 15 年里，我一直這樣做。
但是幾天前，我偶然發現了一個名為“read”的程式的最無用和最意想不到的手冊頁（IMO）。它是讀取用戶輸入的常用程式，許多 shell 腳本都使用它。
這是在我的一個 shell 腳本中使用的。它只是抓取一個變數并輸出它，同時允許最終用戶對其進行編輯：
read -e -p "HOSTip: " -i "${HOSTip}" HOSTip
這個命令花了很多時間在網上搜索才能找到如何以這種方式使用它。手冊頁是零幫助。
任何幫助將不勝感激，以幫助我弄清楚為什么我的機器上似乎不存在使用 read 的正確手冊。
uj5u.com熱心網友回復：
如果你的 shell 是bash，它的內置命令沒有單獨的手冊頁。用于help查看內置插件串列并help <command>獲得有關單個插件的幫助。
$ help
GNU bash, version 5.1.4(1)-release (x86_64-pc-linux-gnu)
These shell commands are defined internally. Type `help' to see this list.
Type `help name' to find out more about the function `name'.
Use `info bash' to find out more about the shell in general.
Use `man -k' or `info' to find out more about commands not in this list.
A star (*) next to a name means that the command is disabled.
job_spec [&] history [-c] [-d offset] [n] or history -anrw [filename>
(( expression )) if COMMANDS; then COMMANDS; [ elif COMMANDS; then COMMA>
. filename [arguments] jobs [-lnprs] [jobspec ...] or jobs -x command [args]
: kill [-s sigspec | -n signum | -sigspec] pid | jobspec >
[ arg... ] let arg [arg ...]
[[ expression ]] local [option] name[=value] ...
alias [-p] [name[=value] ... ] logout [n]
bg [job_spec ...] mapfile [-d delim] [-n count] [-O origin] [-s count] [->
bind [-lpsvPSVX] [-m keymap] [-f filename] [-q name] [-u> popd [-n] [ N | -N]
break [n] printf [-v var] format [arguments]
builtin [shell-builtin [arg ...]] pushd [-n] [ N | -N | dir]
caller [expr] pwd [-LP]
case WORD in [PATTERN [| PATTERN]...) COMMANDS ;;]... es> read [-ers] [-a array] [-d delim] [-i text] [-n nchars]>
cd [-L|[-P [-e]] [-@]] [dir] readarray [-d delim] [-n count] [-O origin] [-s count] >
command [-pVv] command [arg ...] readonly [-aAf] [name[=value] ...] or readonly -p
compgen [-abcdefgjksuv] [-o option] [-A action] [-G glob> return [n]
complete [-abcdefgjksuv] [-pr] [-DEI] [-o option] [-A ac> select NAME [in WORDS ... ;] do COMMANDS; done
compopt [-o| o option] [-DEI] [name ...] set [-abefhkmnptuvxBCHP] [-o option-name] [--] [arg ...>
continue [n] shift [n]
coproc [NAME] command [redirections] shopt [-pqsu] [-o] [optname ...]
declare [-aAfFgiIlnrtux] [-p] [name[=value] ...] source filename [arguments]
dirs [-clpv] [ N] [-N] suspend [-f]
disown [-h] [-ar] [jobspec ... | pid ...] test [expr]
echo [-neE] [arg ...] time [-p] pipeline
enable [-a] [-dnps] [-f filename] [name ...] times
eval [arg ...] trap [-lp] [[arg] signal_spec ...]
exec [-cl] [-a name] [command [argument ...]] [redirecti> true
exit [n] type [-afptP] name [name ...]
export [-fn] [name[=value] ...] or export -p typeset [-aAfFgiIlnrtux] [-p] name[=value] ...
false ulimit [-SHabcdefiklmnpqrstuvxPT] [limit]
fc [-e ename] [-lnr] [first] [last] or fc -s [pat=rep] [> umask [-p] [-S] [mode]
fg [job_spec] unalias [-a] name [name ...]
for NAME [in WORDS ... ] ; do COMMANDS; done unset [-f] [-v] [-n] [name ...]
for (( exp1; exp2; exp3 )); do COMMANDS; done until COMMANDS; do COMMANDS; done
function name { COMMANDS ; } or name () { COMMANDS ; } variables - Names and meanings of some shell variables
getopts optstring name [arg ...] wait [-fn] [-p var] [id ...]
hash [-lr] [-p pathname] [-dt] [name ...] while COMMANDS; do COMMANDS; done
help [-dms] [pattern ...] { COMMANDS ; }
$ help read
read: read [-ers] [-a array] [-d delim] [-i text] [-n nchars] [-N nchars] [-p prompt] [-t timeout] [-u fd] [name ...]
Read a line from the standard input and split it into fields.
Reads a single line from the standard input, or from file descriptor FD
if the -u option is supplied. The line is split into fields as with word
splitting, and the first word is assigned to the first NAME, the second
word to the second NAME, and so on, with any leftover words assigned to
the last NAME. Only the characters found in $IFS are recognized as word
delimiters.
If no NAMEs are supplied, the line read is stored in the REPLY variable.
Options:
-a array assign the words read to sequential indices of the array
variable ARRAY, starting at zero
-d delim continue until the first character of DELIM is read, rather
than newline
-e use Readline to obtain the line
-i text use TEXT as the initial text for Readline
-n nchars return after reading NCHARS characters rather than waiting
for a newline, but honor a delimiter if fewer than
NCHARS characters are read before the delimiter
-N nchars return only after reading exactly NCHARS characters, unless
EOF is encountered or read times out, ignoring any
delimiter
-p prompt output the string PROMPT without a trailing newline before
attempting to read
-r do not allow backslashes to escape any characters
-s do not echo input coming from a terminal
-t timeout time out and return failure if a complete line of
input is not read within TIMEOUT seconds. The value of the
TMOUT variable is the default timeout. TIMEOUT may be a
fractional number. If TIMEOUT is 0, read returns
immediately, without trying to read any data, returning
success only if input is available on the specified
file descriptor. The exit status is greater than 128
if the timeout is exceeded
-u fd read from file descriptor FD instead of the standard input
Exit Status:
The return code is zero, unless end-of-file is encountered, read times out
(in which case it's greater than 128), a variable assignment error occurs,
or an invalid file descriptor is supplied as the argument to -u.
您還可以在“Shell Builtin Commands”下的手冊頁man builtins底部或附近找到他們收集的檔案。bash
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