awk-仅按首次出现时进行拆分 [英] awk - split only by first occurrence

问题描述

我有这样一行:

one:two:three:four:five:six seven:eight

，我想使用awk来使$1成为1，而$2成为two:three:four:five:six seven:eight

and I want to use awk to get $1 to be one and $2 to be two:three:four:five:six seven:eight

我知道我可以通过执行sed来获得它.那就是先用sed更改:的第一个匹配项，然后使用新的定界符将其替换为awk.

I know I can get it by doing sed before. That is to change the first occurrence of : with sed then awk it using the new delimiter.

但是用新的分隔符替换分隔符对我没有帮助，因为我不能保证新的分隔符不会在文本中出现.

However replacing the delimiter with a new one would not help me since I can not guarantee that the new delimiter will not already be somewhere in the text.

我想知道是否有让awk以这种方式运行的选项

I want to know if there is an option to get awk to behave this way

类似这样:

awk -F: '{print $1,$2}'

将打印:

one two:three:four:five:six seven:eight

我也想对$1和$2进行一些操作，所以我不想只替换第一次出现的:.

I will also want to do some manipulations on $1 and $2 so I don't want just to substitute the first occurrence of :.

推荐答案

无任何替换

echo "one:two:three:four:five" | awk -F: '{ st = index($0,":");print $1 "  " substr($0,st+1)}'

index命令查找整个字符串中:"的第一次出现，因此在这种情况下，变量st将设置为4.然后，我使用substr函数从位置开始捕获字符串的所有其余部分. st + 1，如果没有提供结束号，它将转到字符串的末尾.输出为

The index command finds the first occurance of the ":" in the whole string, so in this case the variable st would be set to 4. I then use substr function to grab all the rest of the string from starting from position st+1, if no end number supplied it'll go to the end of the string. The output being

one  two:three:four:five

如果要进行进一步处理，可以始终将字符串设置为变量以进行进一步处理.

If you want to do further processing you could always set the string to a variable for further processing.

rem = substr($0,st+1)

请注意，这已经在Solaris AWK上进行了测试，但是我看不出任何理由不能在其他版本上使用.

Note this was tested on Solaris AWK but I can't see any reason why this shouldn't work on other flavours.

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