使用awk在.CSV逗號分隔文件中添加雙引號

Question

嗨我需要詳細說明一個大的csv文件（20M行）爲每個逗號分隔的字段添加雙引號。 CSV文件中拿到8場昏迷界定如下：

'2016-03-12','12393659','134',,'35533605',189348,9798,gmail.com;live_com.com 
'2016-03-12','12390103','138',,'35438006',5133,1897,google.com 
'2016-03-12','45616164','139',,'01318800',10945593,596633,facebook.com;tumblr.com;t.co 
'2016-03-12','45673436','38',,'86441702',4350985,150327,serving-sys.com;chartboost.com;admarvel.com;mydas.mobi;adap.tv;cloudfront.net 

正如你看到的第一個3場是單引號之間，4日是空白，單引號和6日至8日分隔僅逗號之間的第5位。 我希望得到以下結果（也第四場即使空需要用雙引號）：

"2016-03-12","12393659","134","","35533605","189348","9798","gmail.com;live_com.com" 
"2016-03-12","12390103","138","","35438006","5133","1897","google.com" 
"2016-03-12","45616164","139","","01318800","10945593","596633","facebook.com;tumblr.com;t.co" 
"2016-03-12","45673436","38","","86441702","4350985,"150327","serving-sys.com;chartboost.com;admarvel.com;mydas.mobi;adap.tv;cloudfront.net" 

我部分從而以混合結果sed和awk：

sed -e s/\'//g inpu.csv > output.csv eliminate quotes 
awk '{gsub(/[^,]+/,"\"&\"")}1' output.csv > output1.csv add double quotes 

但第四場不是雙引號，我需要儘可能減少精化時間。 無論如何，幫助AWK以更好的表現來完成所有的事情，並且還有第四場雙引號。 許多thx的幫助。 M.Tave

Answer 1

如果您的數據是真的沒有嵌入引號，換行符或任何簡單的，那麼所有你需要的是：

$ awk -F"'?,'?" -v OFS='","' '{$1=$1; gsub(/^.|$/,"\"")} 1' file 
"2016-03-12","12393659","134","","35533605","189348","9798","gmail.com;live_com.com" 
"2016-03-12","12390103","138","","35438006","5133","1897","google.com" 
"2016-03-12","45616164","139","","01318800","10945593","596633","facebook.com;tumblr.com;t.co" 
"2016-03-12","45673436","38","","86441702","4350985","150327","serving-sys.com;chartboost.com;admarvel.com;mydas.mobi;adap.tv;cloudfront.net" 

Answer 2

給這個AWK的一行一試：

awk -F, -v OFS="," -v re="^'?|'?$" -v q='"' 
        '{for(i=1;i<=NF;i++)if($i)gsub(re,q,$i);else $i=q$i q}7' file 

的想法是，用gsub()到雙引號添加到那些非空字段。那些空的領域，只需將"添加到頭部和尾部。替換正則表達式被定義爲腳本外部的awk變量，用於避免轉義。

它與輸入數據在這裏：

kent$ awk -F, -v OFS="," -v re="^'?|'?$" -v q='"' '{for(i=1;i<=NF;i++)if($i)gsub(re,q,$i);else $i=q$i q}7' f 
"2016-03-12","12393659","134","","35533605","189348","9798","gmail.com;live_com.com" 
"2016-03-12","12390103","138","","35438006","5133","1897","google.com" 
"2016-03-12","45616164","139","","01318800","10945593","596633","facebook.com;tumblr.com;t.co" 
"2016-03-12","45673436","38","","86441702","4350985","150327","serving-sys.com;chartboost.com;admarvel.com;mydas.mobi;adap.tv;cloudfront.net"