如题所述
.sh">
#!/bin/bash
# Your Answer
# filename: if.sh
# chmod +x if.sh
# ./if.sh 2 4 # 2 * 4 = 8
# ./if.sh 2 # Please Enter parm2
# ./if.sh # Please Enter parm1 and parm2
# -n 表示变量非空
# ! 取反; 即为空
# $1 $2 表示传递的第一个第二个参数
if [ ! -n "$1" ]; then
echo Please Enter parm1 and parm2
exit
fi
if [ ! -n "$2" ]; then
echo Please Enter parm2
exit
fi
echo $1 \* $2 = `expr $1 \* $2`
#!/bin/bash
# Your Answer
# filename: if.sh
# chmod +x if.sh
# ./if.sh 2 4 # 2 * 4 = 8
# ./if.sh 2 # Please Enter parm2
# ./if.sh # Please Enter parm1 and parm2
# -n 表示变量非空
# ! 取反; 即为空
# $1 $2 表示传递的第一个第二个参数
if [ ! -n "$1" ]; then
echo Please Enter parm1 and parm2
exit
fi
if [ ! -n "$2" ]; then
echo Please Enter parm2
exit
fi
echo $1 \* $2 = `expr $1 \* $2`
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