########################################################### 1. 如果用man for你??椴壞較嚓P?橢??n???r可以使用 help for 查看manual,help是?ｉT查看SHELL中的函?滌梅?br /> ########################################################### ---------------------------------------------------------- [root@pasprd tmp]# help GNU bash, version 2.05b.0(1)-release (i386-redhat-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.
%[DIGITS | WORD] [&] (( expression )) . filename : [ arg... ] [[ expression ]] alias [-p] [name[=value] ... ] bg [job_spec] bind [-lpvsPVS] [-m keymap] [-f fi break [n] builtin [shell-builtin [arg ...]] case WORD in [PATTERN [| PATTERN]. cd [-L|-P] [dir] command [-pVv] command [arg ...] compgen [-abcdefgjksuv] [-o option complete [-abcdefgjksuv] [-pr] [-o continue [n] declare [-afFirtx] [-p] name[=valu dirs [-clpv] [+N] [-N] disown [-h] [-ar] [jobspec ...] echo [-neE] [arg ...] enable [-pnds] [-a] [-f filename] eval [arg ...] exec [-cl] [-a name] file [redirec exit [n] export [-nf] [name[=value] ...] or false fc [-e ename] [-nlr] [first] [last fg [job_spec] for NAME [in WORDS ... ;] do COMMA for (( exp1; exp2; exp3 )); do COM function NAME { COMMANDS ; } or NA getopts optstring name [arg] hash [-lr] [-p pathname] [-dt] [na help [-s] [pattern ...] history [-c] [-d offset] [n] or hi if COMMANDS; then COMMANDS; [ elif jobs [-lnprs] [jobspec ...] or job kill [-s sigspec | -n signum | -si let arg [arg ...] local name[=value] ... logout popd [+N | -N] [-n] printf format [arguments] pushd [dir | +N | -N] [-n] pwd [-PL] read [-ers] [-u fd] [-t timeout] [ readonly [-anf] [name[=value] ...] return [n] select NAME [in WORDS ... ;] do CO set [--abefhkmnptuvxBCHP] [-o opti shift [n] shopt [-pqsu] [-o long-option] opt source filename suspend [-f] test [expr] time [-p] PIPELINE times trap [arg] [signal_spec ...] or tr true type [-afptP] name [name ...] typeset [-afFirtx] [-p] name[=valu ulimit [-SHacdflmnpstuv] [limit] umask [-p] [-S] [mode] unalias [-a] [name ...] unset [-f] [-v] [name ...] until COMMANDS; do COMMANDS; done variables - Some variable names an wait [n] while COMMANDS; do COMMANDS; done { COMMANDS ; }
---------------------------------------------------------- [root@pasprd tmp]# help for for: for NAME [in WORDS ... ;] do COMMANDS; done The `for' loop executes a sequence of commands for each member in a list of items. If `in WORDS ...;' is not present, then `in "$@"' is assumed. For each element in WORDS, NAME is set to that element, and the COMMANDS are executed. for ((: for (( exp1; exp2; exp3 )); do COMMANDS; done Equivalent to (( EXP1 )) while (( EXP2 )); do COMMANDS (( EXP3 )) done EXP1, EXP2, and EXP3 are arithmetic expressions. If any expression is omitted, it behaves as if it evaluates to 1. ----------------------------------------------------------
