【求助】关于2> /dev/null
harryp
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1#
发表于 2005-12-04 23:06
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harryp
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1#
发表于 2005-12-04 23:06
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li-jiahuan
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2#
发表于 2005-12-05 08:42
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经过不完全测试代码:[No.483 08:41:38 ~ ]# nslookup -sil 10.3.51.41Server: 10.3.51.41 Address: 10.3.51.41#53 41.51.3.10.in-addr.arpa name = huan.linux.net. [No.484 08:42:29 ~ ]# nslookup -sil 10.3.51.41 | grep name 41.51.3.10.in-addr.arpa name = huan.linux.net. [No.485 08:43:41 ~ ]# nslookup -sil 10.3.51.41 | grep name | awk '{print $4}' huan.linux.net. 发现并不需要 2>/dev/null的意思是把标错误扔到位桶里 也就是你将看不见错误提示 给个例子
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感谢dearvoid帮助我明白这点 代码:[No.491 08:49:24 ~ ]# for ip in {1..254}> do > fping 10.3.51.$ip | grep alive > done 10.3.51.1 is alive 10.3.51.2 is alive 10.3.51.3 is alive ICMP Host Unreachable from 10.3.51.41 for ICMP Echo sent to 10.3.51.4 ICMP Host Unreachable from 10.3.51.41 for ICMP Echo sent to 10.3.51.4 ICMP Host Unreachable from 10.3.51.41 for ICMP Echo sent to 10.3.51.4 ICMP Host Unreachable from 10.3.51.41 for ICMP Echo sent to 10.3.51.5 ICMP Host Unreachable from 10.3.51.41 for ICMP Echo sent to 10.3.51.5 ICMP Host Unreachable from 10.3.51.41 for ICMP Echo sent to 10.3.51.5 ............................... [No.492 08:50:47 ~ ]# for ip in {1..254}; do fping 10.3.51.$ip 2>/dev/null | grep alive; don e 10.3.51.1 is alive 10.3.51.2 is alive 10.3.51.3 is alive 10.3.51.10 is alive 10.3.51.15 is alive ................................. 
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harryp
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3#
发表于 2005-12-06 07:53
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li-jiahuan
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4#
发表于 2005-12-06 08:33
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