问题描述
使用一行Perl代码，最简单的方法是打印两个模式之间的所有行(不包括带有模式的行)吗?
Using one line of Perl code, what is the shortest way possible to print all the lines between two patterns not including the lines with the patterns?
如果这是file.txt:
If this is file.txt:
aaa
START
bbb
ccc
ddd
END
eee
fff
我要打印此:
bbb
ccc
ddd
我可以使用以下方法获得大部分信息:
I can get most of the way there using something like this:
perl -ne 'print if (/^START/../^END/);'
不过，其中包括START和END行.
我可以像这样完成工作:
I can get the job done like this:
perl -ne 'if (/^START/../^END/) { print unless (/^(START)|(END)/); };' file.txt
但这似乎是多余的.
我真正想做的是使用像这样的lookbehind和lookahead断言:
What I'd really like to do is use lookbehind and lookahead assertions like this:
perl -ne 'print if (/^(?<=START)/../(?=END)/);' file.txt
但这是行不通的，我认为我的正则表达式有些错误.
But that doesn't work and I think I've got something just a little bit wrong in my regex.
这些只是我尝试过的一些不产生任何输出的变体:
These are just some of the variations I've tried that produce no output:
perl -ne 'print if (/^(?<=START)/../^.*$(?=END)/);' file.txt
perl -ne 'print if (/^(?<=START)/../^.*(?=END)/);' file.txt
perl -ne 'print if (/^(?<=START)/../(?=END)/);' file.txt
perl -ne 'print if (/^(?<=START)/../.*(?=END)/);' file.txt
perl -ne 'print if (/^(?<=START)/../^.*(?=END)/);' file.txt
perl -ne 'print if (/^(?<=START)/../$(?=END)/);' file.txt
perl -ne 'print if (/^(?<=START)/../^(?=END)/);' file.txt
perl -ne 'print if (/^(?<=START)/../(?=^END)/);' file.txt
perl -ne 'print if (/^(?<=START)/../.*(?=END)/s);' file.txt
推荐答案
读取整个文件，进行匹配并打印.
Read the whole file, match, and print.
perl -0777 -e 'print <> =~ /START.*?\n(.*?)END.*?/gs;' file.txt
如果单独在线，可能会在START|END之后下降.*?.然后将\n放到各段之间的空白行.
May drop .*? after START|END if alone on line.Then drop \n for a blank line between segments.
读取文件，用START|END分隔行，打印@F的所有奇数
Read file, split line by START|END, print every odd of @F
perl -0777 -F"START|END" -ane 'print @F[ grep { $_ & 1 } (0..$#F) ]' file.txt
使用END { }块进行额外的处理.将}{用于END { }.
Use END { } block for extra processing. Uses }{ for END { }.
perl -ne 'push @r, $_ if (/^START/../^END/); }{ print "@r[1..$#r-1]"' file.txt
仅在文件中的单个此类段中起作用.
Works as it stands only for a single such segment in the file.
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