TQ2440网卡移植问题

在串口终端显示如截图捕获1，net_set是我用vi编辑器敲的
net_set的内容如截图捕获2，也是用vi敲的
net.conf的内容如截图捕获3，也是用vi敲的
请问为什么出现如截图捕获1 的问题？？？？？？
但是能ping通如下：
[root@EmbedSky /]# ping 10.1.13.67
PING 10.1.13.67 (10.1.13.67): 56 data bytes
64 bytes from 10.1.13.67: seq=0 ttl=64 time=2.770 ms
64 bytes from 10.1.13.67: seq=1 ttl=64 time=0.912 ms
64 bytes from 10.1.13.67: seq=2 ttl=64 time=0.905 ms
64 bytes from 10.1.13.67: seq=3 ttl=64 time=0.917 ms
64 bytes from 10.1.13.67: seq=4 ttl=64 time=0.943 ms
64 bytes from 10.1.13.67: seq=5 ttl=64 time=0.918 ms
64 bytes from 10.1.13.67: seq=6 ttl=64 time=0.997 ms
64 bytes from 10.1.13.67: seq=7 ttl=64 time=0.944 ms
64 bytes from 10.1.13.67: seq=8 ttl=64 time=0.997 ms
64 bytes from 10.1.13.67: seq=9 ttl=64 time=1.031 ms
64 bytes from 10.1.13.67: seq=10 ttl=64 time=0.964 ms
^C
--- 10.1.13.67 ping statistics ---
11 packets transmitted, 11 packets received, 0% packet loss
round-trip min/avg/max = 0.905/1.118/2.770 ms
[root@EmbedSky /]#

问题解决：
看到/sbin/net_set: line 4:if[-f :not found，因为我是看着移植手册敲的，检查再三，字母没敲错，所以最有可能的错是空格问题。我一一验证其空格最后得出正确写法为：if空格[空格-f 空格/etc/net.conf空格];then

确实，好多人遇到类似的问题，都是空格害的。