虽然学过Linux Shell编程，但由于编写Shell脚本的机会实在是比较少(通常在项目初期搭建开发环境时编写得比较多一些)，所以一些语法久而久之就会忘了，一个简单的语法去翻书效率实在是慢，所以就个人整理了一个表格，由于我用的编程语言是C/C++，所以在编程的时候往往脑海里面首先浮现的是用C语言怎么去编写它，所以我干脆拿C语言的语法来和Shell编程的语法作个对比表，这样查起来就方便了，哈：

(注：不知道为什么从WORD中粘帖的表格在这里显示会不完整，在编辑的时候又是正常的，闷)

要实现的功能

C语言编程

Linux Shell脚本编程

程序/脚本的参数传递

int main(int argc, char** argv)

{

if (argv != 4) {

printf( “Usage: %s arg1 arg2 arg3”, argv[0] );

return 1;

}

printf(“arg1:%s\n”,argv[1]);

printf(“arg2:%s\n”,argv[2]);

printf(“arg3:%s\n”,argv[3]);

return 0;

}

#!/bin/sh

if [ $# -lt 3 ]; then

echo "Usage: `basename $0` arg1 arg2 arg3" >&2

exit 1

fi

echo "arg1: $1"

echo "arg2: $2"

echo "arg3: $3"

exit 0

int main(int argc, char** argv)

{

int i;

for (i=1; i<=argc;i++) {

printf(“arg:%s\n”,argv[i]);

}

return 0;

}

#!/bin/sh

while [ $# -ne 0 ]

do

echo "arg: $1"

shift

done

逻辑/数值运算

if (d == 0)

if [ "$D" -eq "0" ] ; then

if (d != 0)

if [ "$D" -ne "0" ] ; then

if (d > 0)

if [ "$D" -gt "0" ] ; then

if (d < 0)

if [ "$D" -lt "0" ] ; then

if (d <= 0)

if [ "$D" -le "0" ] ; then

if (d >= 0)

if [ "$D" -ge "0" ] ; then

字符串比较

if (strcmp(str,”abc”)==0) {

}

if [ "$STR" != "abc" ]; then

fi

输入和输出

scanf(“%d”,&D);

read D

printf( “%d”, D);

echo –n $D

printf( “%d”,D);

echo $D

printf( “Press any to continue...”);

char ch=getchar();

printf( “\nyou pressed: %c\n”, ch );

#!/bin/sh

getchar()

{

SAVEDTTY=`stty -g`

stty cbreak

dd if=/dev/tty bs=1 count=1 2> /dev/null

stty -cbreak

stty $SAVEDTTY

}

echo -n "Press any key to continue..."

CH=`getchar`

echo ""

echo "you pressed: $CH"

read D <&3

程序/脚本的控制流程

if (isOK) {

//1

} else if (isOK2) {

//2

} else {

//3

}

if [ isOK ]; then

#1

elif [ isOK2 ]; then

#2

else

#3

fi

switch (d)

{

case 1:

printf(“you select 1\n”);

break;

case 2:

case 3:

printf(“you select 2 or 3\n”);

break;

default:

printf(“error\n”);

break;

};

case $D in

1) echo "you select 1"

;;

2|3) echo "you select 2 or 3"

;;

*) echo "error"

;;

esac

for (int loop=1; loop<=5;loop++) {

printf( “%d”, loop);

}

for loop in 1 2 3 4 5

do

echo $loop

done

do {

sleep(5);

} while( !isRoot );

IS_ROOT=`who | grep root`

until [ "$IS_ROOT" ]

do

sleep 5

done

counter=0;

while( counter < 5 ) {

printf( “%d\n”, counter);

counter++;

}

COUNTER=0

while [ $COUNTER -lt 5 ]

do

echo $COUNTER

COUNTER=`expr $COUNTER + 1`

done

while (1) {

}

while :

do

done

break;

break或break n，n表示跳出n级循环

continue;

continue

函数与过程的定义

void hello()

{

printf( “hello\n” );

}

…

//函数调用

hello();

hello()

{

Echo “hello”

} 或者

function hello()

{

Echo “hello”

}

…

#函数调用

hello

函数的参数和返回值

int ret = doIt();

if (ret == 0) {

printf( “OK\n” );

}

doIt

if [ “$?” –eq 0 ] ; then

echo “OK”

fi

或者

RET = doIt

if [ “$RET” –eq “0” ] ; then

echo “OK”

fi

int sum(int a,int b)

{

return a+b;

}

int s = sum(1,2);

printf(“the sum is: %d\n”, s);

sum()

{

echo -n "`expr $1 + $2`"

}

S=`sum 1 2`

echo "the sum is: $S"

bool isOK() { return false; }

if (isOK) {

printf( “YES\n” );

} else {

printf( “NO\n” );

}

isOK()

{

return 1;

}

if isOK ; then

echo "YES"

else

echo "NO"

fi