helpコマンドで表示できます。
[root@centos8_1 ~]# help
GNU bash, バージョン 4.4.20(1)-release (x86_64-redhat-linux-gnu)
これらのシェルコマンドは内部で定義されています。`help' と入力して一覧を参照してください。
`help 名前' と入力すると `名前' という関数のより詳しい説明が得られます。
'info bash' を使用するとシェル全般のより詳しい説明が得られます。
`man -k' または info を使用すると一覧にないコマンドのより詳しい説明が得られます。
名前の後にアスタリスク (*) がある場合はそのコマンドが無効になっていることを意味します。
job_spec [&] history [-c] [-d offset] [n] または history -anrw [filename] または histor>
(( expression )) if COMMANDS; then COMMANDS; [ elif COMMANDS; then COMMANDS; ]... [ else CO>
. filename [arguments] jobs [-lnprs] [jobspec ...] または jobs -x command [args]
: kill [-s sigspec | -n signum | -sigspec] pid | jobspec ... または kill -l >
[ arg... ] let 引数 [引数 ...]
[[ expression ]] local [option] name[=value] ...
alias [-p] [name[=value] ... ] logout [n]
bg [job_spec ...] mapfile [-d delim] [-n count] [-O origin] [-s count] [-t] [-u fd] [-C call>
bind [-lpsvPSVX] [-m keymap] [-f filename] [-q name] [-u name] [-r keyseq] > 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 ;;]... esac read [-ers] [-a array] [-d delim] [-i text] [-n nchars] [-N nchars] [-p pr>
cd [-L|[-P [-e]] [-@]] [dir] readarray [-n count] [-O origin] [-s count] [-t] [-u fd] [-C callback] [-c>
command [-pVv] command [arg ...] readonly [-aAf] [name[=value] ...] または readonly -p
compgen [-abcdefgjksuv] [-o option] [-A action] [-G globpat] [-W wordlist] > return [n]
complete [-abcdefgjksuv] [-pr] [-DE] [-o option] [-A action] [-G globpat] [> select NAME [in WORDS ... ;] do COMMANDS; done
compopt [-o|+o option] [-DE] [name ...] set [-abefhkmnptuvxBCHP] [-o option-name] [--] [arg ...]
continue [n] shift [n]
coproc [NAME] command [redirections] shopt [-pqsu] [-o] [optname ...]
declare [-aAfFgilnrtux] [-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 [arguments ...]] [redirection ...] true
exit [n] type [-afptP] name [name ...]
export [-fn] [name[=value] ...] または export -p typeset [-aAfFgilnrtux] [-p] name[=value] ...
false ulimit [-SHabcdefiklmnpqrstuvxPT] [limit]
fc [-e ename] [-lnr] [first] [last] または fc -s [pat=rep] [command] 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 ; } または name () { COMMANDS ; } 変数 - 変数の名前とその意味
getopts optstring name [arg] wait [-n] [id ...]
hash [-lr] [-p pathname] [-dt] [name ...] while COMMANDS; do COMMANDS; done
help [-dms] [pattern ...] { COMMANDS ; }
[root@centos8_1 ~]#
[root@centos8_1 ~]#
個別ではtype -a で表示できます
[root@centos8_1 ~]# type -a ulimit
ulimit はシェル組み込み関数です
ulimit は /usr/bin/ulimit です
[root@centos8_1 ~]#