怎么获取文件中的一段内容？

wsryyffs66

文件aa.txt
[aa]
aa1
dd2
dd3
dd4

[bb]
dd5
dd6
dd7
xx8
dd9
5510

要获取
[aa]
aa1
dd2
dd3
dd4

怎么实现？

ly5066113

1. awk -v RS= '/^\[aa]/' aa.txt

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wsryyffs66

ly5066113 发表于 2011-07-06 16:31

    好用了，但不太理解，麻烦请指导一下，谢谢！

Shell_HAT

回复 3# wsryyffs66


设置RS之后，行分隔符就变了，参考：

1. awk -v RS= '$1=$1' urfile

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lionfun

回复 4# Shell_HAT

Shell_HAT老大，我有一个地方不太明白，就是awk -v RS= '/^\[aa]/' aa.txt以后为什就只显示：
[aa]
aa1
dd2
dd3
dd4
按你说的以[aa]作为行分隔符咯？那下面的为什么不显示
[bb]
dd5
dd6
dd7
xx8
dd9
5510

yinyuemi

回复 5# lionfun


   

`RS == "\n"'
     Records are separated by the newline character (`\n').  In effect,
     every line in the data file is a separate record, including blank
     lines.  This is the default.

`RS == ANY SINGLE CHARACTER'
     Records are separated by each occurrence of the character.
     Multiple successive occurrences delimit empty records.

`RS == ""'
     Records are separated by runs of blank lines.  When `FS' is a
     single character, then the newline character always serves as a
     field separator, in addition to whatever value `FS' may have.
     Leading and trailing newlines in a file are ignored.

`RS == REGEXP'
     Records are separated by occurrences of characters that match
     REGEXP.  Leading and trailing matches of REGEXP delimit empty
     records.  (This is a `gawk' extension; it is not specified by the
     POSIX standard.)

Shell_HAT

回复 5# lionfun


那不是把[a]作为列分隔符，而是把RS设置成空，类似：

1. awk -v RS="" '/^\[aa]/' aa.txt

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详见6楼第三段

lionfun

回复 7# Shell_HAT


    是啊……发现了！谢谢， 同时也谢谢ss兄！

kr_zhang

回复 6# yinyuemi


    弱弱问一下，这些说明都在那能看到 ？

yinyuemi

回复 9# kr_zhang


    info awk
    man awk
    google 'The GNU Awk User's Guide'