最後更新: 2016-02-18

介紹

ash (Kenneth Almquist's ash shell)

A lightweight (92K) Bourne compatible shell.

Ash is also fairly popular in embedded Linux systems; its code was incorporated into the BusyBox

Config File

$HOME/.profile

/etc/profile

#!/bin/sh
[ -f /etc/banner ] && cat /etc/banner

export PATH=/bin:/sbin:/usr/bin:/usr/sbin
export HOME=$(grep -e "^${USER:-root}:" /etc/passwd | cut -d ":" -f 6)
export HOME=${HOME:-/root}
export PS1='\u@\h:\w\$ '

[ -x /bin/more ] || alias more=less
[ -x /usr/bin/vim ] && alias vi=vim || alias vim=vi

[ -z "$KSH_VERSION" -o \! -s /etc/mkshrc ] || . /etc/mkshrc

[ -x /usr/bin/arp ] || arp() { cat /proc/net/arp; }
[ -x /usr/bin/ldd ] || ldd() { LD_TRACE_LOADED_OBJECTS=1 $*; }

#### Add by datahunter ####
export PS1='\u@\h:\W\$ '
alias u='cd ..'
alias ll='ls -lsh --color=yes'
alias la='ls -lah --color=yes'
alias p="ping -c 3 8.8.8.8"
alias rm='rm -i'
alias mv='mv -i'
alias cp='cp -i'

Function

#!/bin/ash

myfunction(){
        echo "I 'm function"
}

myfunction

while

Syntax

#!/bin/ash

while [ true ]; do
    sleep 3
    echo "Testing"
done

break & continue

break [ num ]
continue [ num ]

if

Syntax

if list; then 
    list
elif list; then
    list
else 
    list
fi

Example

# -eq -ne

if [ $? -eq 0 ]; then
    ping -q -c 4 8.8.8.8
    if [ $? -ne 0 ]; then
        /usr/local/bin/myscript
    fi
fi

for

services='service1 service2 service3'

for s in $services ; do
  START "$s"
done

Example

# 1 - Disallow access fb, youtube

#!/bin/ash

flagfile="/tmp/BlockDomain.txt"
DisableTime="09 10 11 14 15 16 17 18"

now=`date +"%H"`
# Check Block
for t in $DisableTime
do
        if [ $now -eq $t ]; then
                if [ -e $flagfile ]; then
                        echo "No need run Block"
                        touch $flagfile                  # for checking
                        exit
                fi
                echo "Run Block"
                echo 'address=/facebook.com/127.0.0.1' >> /etc/dnsmasq.conf
                echo 'address=/youtube.com/127.0.0.1'  >> /etc/dnsmasq.conf
                killall dnsmasq
                dnsmasq --log-async
                pidof dnsmasq
                touch $flagfile
                exit
        fi
done
# Allow
if [ -e $flagfile ]; then
        echo "Run Allow"
        # refresh /etc/dnsmasq.conf
        service restart_dnsmasq
        rm -f $flagfile
else
        echo "No need run Allow"
fi

DOC

http://linux.die.net/man/1/ash