个人整理的Linux Shell语法速查表（用C语言语法来作对比）
转载自: http://blog.csdn.net/kwiner/archive/2009/04/05/4049640.aspx
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：
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
转载自: http://blog.csdn.net/kwiner/archive/2009/04/05/4049640.aspx
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：
|
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 |
