函数用法

函数定义：

# func_name 函数名    
function func_name(){  
    #函数体内容  
}  
或  
func_name(){  
    #函数体内容  
}  

函数调用：

func_name parm

获取函数还回值：

sum_xdr()
{
	count=$1;
	count=$[count*10];
	echo $count;    	#这里是使用echo语句，将结果输出到标准输出上，所以在主程序中可以使用变量接收
}

ret=`sum_xdr 3`;

1、函数调用（只能包含字符）

#!/bin/sh
char_name()
{
	_Letters_Only=$1    #
	_Letters_Only=`echo $1|awk ‘{if($0~/[^a-zA-X]/) print "1"}‘` #只能包含字符
	if [ "$_Letters_Only" != "" ]
	then
		return 1
	else
		return 0
	fi
}
 
name_error()
{
	echo "[email protected] contains errors ,it ,must contain only letters"
}
 
while :
do
	echo -n "what is your first name :"
	read F_Name
	if char_name $F_Name
	then
		break
	else
		name_error $F_Name
	fi
done

2、字符串转大写函数 str_to_upper

#!/bin/sh
str_to_upper()
{
    _str=$1
    if [ $# -ne 1 ]; then
        echo "number_file: I need a string to convert please "
        return 1
    fi
    echo [email protected] | tr ‘[a-z]‘ ‘[A-Z]‘
}

3、列出文本文件的行号  number_file脚本

#!/bin/sh
number_file()
{
	_Filename=$1
	if [ $# -ne 1 ]; then
		echo "number_file: I need a filename to number"
		return 1
	fi
	loop=1
	while read Line
	do
		echo "$loop :$Line"
		loop=`expr $loop + 1`
	done <$_Filename
}  

4、判断字符串是否为大写 is_upper脚本

#!/bin/sh
is_upper()
{
	if [ $# -ne 1 ]; then
	echo "is_upper:I need a string to test OK"
		return 1
	fi
	_Is_Upper=`echo $1|awk ‘{if($0~/[^A-Z]/) print "1"}‘`
	if [ "$_Is_Upper" != "" ]
	then
		return 1
	else
		return 0
	fi
}
echo  -n "Enter the filename :"
read FileName
if is_upper $FileName ; then
	echo "Great it‘s upper case"
else
	echo "Sorry it‘s not upper case"
fi

要测试字符串是否为小写,只需要在is_upper中替换相应的awk语句即可。此为

is_lower
_Is_Lower=`echo $1|awk ‘{if($0~/[^a-z]/) print "1"}‘`

5、 测试字符串长度 check_length脚本

#!/bin/sh
check_length()
{
	_str=$1
	_max=$2
	if [ $# -ne 2 ]; then
		echo "check_length; I need a string and max length the string should be "
		return 1
	fi
	#check the length of the string
	_Length=`echo $_str|awk ‘{print length($0)}‘`
	if [ "$_Length" -gt "$_max" ]; then
		return  1
	else
		return 0
	fi
}
while :
do
	echo "Enter your First name :"
	read Name
	if check_length $Name 10
	then
		break
	else
		echo "The name field is too long 10 charater max "
	fi
done

使用wc命令接收键盘操作输入时有一个误操作。如果用户输入一个名字后,点击了几次空格键

wc也将这些空格作为字符串的一部分。因而给出其错误的长度。awk在读取键盘时缺省截去字符串末尾处空格。

6、chop函数删除字符串前面的字符 chop脚本

#!/bin/sh
chop()
{
	# to call: chop string how_many_charts_to_chop
	_str=$1
	_chop=$2
	chop=`expr $_chop + 1 `
	if [ $# -ne 2 ]; then
		echo  "check_length : I need  a string and how manay characters to chop "
		return 1
	fi
	_Length=`echo $_str|awk ‘{print length($0)}‘`
	if [ "$_Length" -lt "$_chop" ]; then
		echo "sorry you have asked to chop more characters than there ara in the string "
		return 1
	fi
	echo $_str |awk ‘{print substr($1,‘$_chop‘)}‘
}

来自为知笔记(Wiz)