AWK过滤小于0的为啥会把空值过滤出来呢！

wan_qin

如下面命令，我想过滤出小于0的数据，为啥空值也过滤出来了呢！

[root@znwy-11 pm]# awk -F "|" -vOFS="|" 'NR<100{if($30<0 || $31<0) print $4,$5,$30,$31}' *F_L_C_EUTRANCELLTDD_H.csv
11-860-1-73|长沙桐梓坡西路与麓云路交叉口（中联重科拉远）HFD-D3910378589PT-73||
11-216-1-12|长沙省政府东南(长沙651仓库拉远)HF-D3900459579PT-12||
11-537-1-73|长沙大陶精密仪器HFD-D3910378540PT-73||
11-860-1-72|长沙桐梓坡西路与麓云路交叉口（中联重科拉远）HFD-D3910378589PT-72||
11-591-1-71|长沙望城区工业职院东南角HFD-D5900378619PT-71||
11-1122-1-152|长沙大学洪山6栋HL-D3900983109PT-152||

wan_qin

[root@znwy-11 pm]# awk -F "|" -vOFS="|" '{if($30<0 && $30!="" || $31<0 && $31!="") print $4,$5,$30,$31}' *F_L_C_EUTRANCELLTDD_H.csv
Nokia-104201-MRBTS-542447-LNBTS-542447-LNCEL-78|ZZHHTXinTangXiLuChengTieNBNF-AirScale542447PT-78|0|-3
Nokia-104201-MRBTS-542447-LNBTS-542447-LNCEL-77|ZZHHTXinTangXiLuChengTieNBNF-AirScale542447PT-77|0|-7
Nokia-102302-MRBTS-279469-LNBTS-279469-LNCEL-131|xtaxiangtanxianyunhuqiaojiandongcunNL-FSIH279469PT-131|0|-1

cfwyy

试一下空和0比较：

1. awk 'BEGIN{print ""<0}'
   

复制代码

结果是 1