Usage of Grep???help!!! - 未名空间MITBBS历史存档

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Usage of Grep???help!!!

Usage of Grep???help!!!# Programming - 葵花宝典

s*f2005-05-05 07:05

1 楼

I have data files with format like this:
year,mon,day,data.....
All are numbers and are seperated by coma. Can someone give me some suggestion
how I can use grep to extract the data at certain month, say, March-May.
I tried :
grep "^[[:digit:]\{\4\}[, ][3-5]]" inputfile >outputfile
It doesn't work.
Thanks!!!

a*n2005-05-05 07:05

2 楼

awk -F, '{if($2==4 || $2==5) print}' inputfile > outputfile

【在 s*******f 的大作中提到】

: I have data files with format like this:
: year,mon,day,data.....
: All are numbers and are seperated by coma. Can someone give me some suggestion
: how I can use grep to extract the data at certain month, say, March-May.
: I tried :
: grep "^[[:digit:]\{\4\}[, ][3-5]]" inputfile >outputfile
: It doesn't work.
: Thanks!!!

c*t2005-05-05 07:05

3 楼

egrep "March|May" ..?

【在 s*******f 的大作中提到】

a*n2005-05-05 07:05

4 楼

A perl solution:
#!/usr/bin/perl
# To run: perl test.pl inputfile
while(<>){
my @line = split(",",$_);
print $_ if($line[1]==3 || $line[1]==4 || $line[1]==5);
}

【在 s*******f 的大作中提到】

i*h2005-05-05 07:05

5 楼

What do you mean it doesn't work? No match or too many matches?
1. Why do you need a space in [, ], the format does not imply that.
2. The outside bracket is not necessary.
3. And you don't need another "\" before "4".
Try
^[:digit:]\{4\},[3-5]

【在 s*******f 的大作中提到】