awk只打印两个模式之间的行,删除第一个匹配

时间:2015-03-06 08:52:50

标签: regex bash awk

这个在两种模式之间打印

printf "/n"| openssl s_client -showcerts -connect www.google.com:443 | awk '/-----BEGIN CERTIFICATE-----/,/-----END CERTIFICATE-----/'

然后这个删除第一个匹配集,然后打印所有多余的垃圾

printf "/n"| openssl s_client -showcerts -connect www.google.com:443 | awk '/-----BEGIN CERTIFICATE-----/{f=1;++c} !(f && c==2); /-----END CERTIFICATE-----/{f=0}'

我想得到第二个结果,除了模式匹配之外我只能使用两个awk。

printf "/n"| openssl s_client -showcerts -connect www.google.com:443 | awk '/-----BEGIN CERTIFICATE-----/,/-----END CERTIFICATE-----/' | awk '/-----BEGIN CERTIFICATE-----/{f=1;++c} !(f && c==2); /-----END CERTIFICATE-----/{f=0}'

但如果有可能,我想在一个地方做。

1 个答案:

答案 0 :(得分:1)

这似乎与this question非常相似,我的调整答案如下:

sed -n '/-----BEGIN CERTIFICATE----/,/-----END CERTIFICATE-----/ { // { x; s/$/./; x; }; x; /.../ { x; p; x; }; x; }' filename

那是

/-----BEGIN CERTIFICATE----/,/-----END CERTIFICATE-----/ {
  // {           
    x
    s/$/./      #  keep a counter of boundary lines in the hold buffer
    x
  }
  x             # inspect the counter
  /.../ {       # if counter >= 3
    x
    p           # print the line
    x
  }
  x
}               # with -n, falling off the end here will not lead to printing.

或者,我能想到的最好的awk是

awk '/----BEGIN CERTIFICATE----/ { flag = 1; ++ctr } flag && ctr >= 2 { print } /-----END CERTIFICATE-----/ { flag = 0 }' filename

更可读:

/----BEGIN CERTIFICATE----/ {  # beginning of a range:
  flag = 1                     # raise flag that we're in one
  ++ctr                        # count in which one
}
flag && ctr >= 2 { print }     # print only if in a range and not in the first
/-----END CERTIFICATE-----/ {  # when leaving
  flag = 0                     # lower flag
}