bash – 替换文件中的列,但保留空格格式

awk 'FNR==NR {split($0,a,",");b[a[2]]=a[1];next} {n=split($0,d,/[^[:space:]]*/);if(b[$4])$4=b[$4];for(i=1;i<=n;i++) printf("%s%s",d[i],$i);print ""}' fileB fileA

它将空间存储在一个数组中,以便以后可以重用它

例：

cat fileA
xxx    xxx   xxx Z0002   not change this
xxx   xxx  Z0002 zzz
xxx Z000223213 xxx Z0002 xxx xxx xxx Z0002

cat fileB
3100,3000
W0002,Z0002

awk 'FNR==NR {split($0,$i);print ""}' fileB fileA
xxx    xxx   xxx  W0002   not change this
xxx   xxx  Z0002 zzz
xxx Z000223213 xxx  W0002 xxx xxx xxx Z0002

一些更具可读性及其工作原理：

awk '
FNR==NR {                           # For the first file "fileB"
    split($0,")                 # Split it to an array "a" using "," as separator 
    b[a[2]]=a[1]                    # Store the data in array "b" using second column as index
    next                            # Skip to next record
    }
    {                               # Then for the file "fileA"
    n=split($0,/[^[:space:]]*/)   # Split the spaces inn group and store them in array "d"
    if(b[$4])                       # If array "b" as data for field "4"
        $4=b[$4]                    # Change filed "4" to data found in array "b"
    for(i=1;i<=n;i++)               # Loop trough all field in the line
        printf("%s%s",$i)      # print correct separator and data
    print ""                        # Add new line at the end
    }
' fileB fileA                       # Read the files.