求助匹配模式n至m次的問題

qinghan1125

如下，第二個awk輸出為空，原意是想數(shù)值匹配1至3次

sbmp:/tmp/ou # awk '{if($1~/[0-9]*\.[0-9]*\.[0-9]*\.[0-9]*/) print $1}' /etc/hosts
127.0.0.1
127.0.0.2
10.69.18.213
192.168.1.113

sbmp:/tmp/ou #  awk '{if($1~/[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}/) print $1}' /etc/hosts

lululau

awk  --re-interval '$1 ~ /[0-9]{1,3}\.[0-9]......./'

qinghan1125

請教我寫的那個有什么問題呢

wqfhenanxc

man awk

--re-interval
              Enable the use of interval expressions in regular expression matching (see Regular , Expressionsbelow).  Interval expressions were not traditionally available in the AWK language.  The POSIX standard added them, to make awk and egrep consistent with each other.  However, their use is likely to break old AWK programs, so gawk only provides them if they are requested with this option, or when --posix is specified.

iori809

其實(shí)主要是AWK的版本問題在 POSIX之前的版本大括號不可使用。 之后就可以 了