自2D数组以来，这是GNU awk中的一个:

Here's one in GNU awk since using 2D arrays:

$ awk '
BEGIN {
    FS=OFS="\t" }                          # set the delimiters
{
    sub(/\r/,"",$NF)                       # in case of \r\n line endings
    a[NR][1]                               # define array element
    n=split($0,a[NR],FS)                   # split record to a[NR]
    a[NR][4]=$1 OFS $2 OFS $3 OFS $4       # gather constants to one element
    if(NR==1)
        a[NR][4]="DOC_DATE" OFS a[NR][4] OFS "QTY"
}
END {                                      # everything is in memory
    print a[1][4];                         # header print
    for(j=5;j<=n;j++)                      # loop all data fields
        for(i=2;i<=NR;i++)                 # loop all records
            print a[1][j],a[i][4],a[i][j]  # output
}' file
DOC_DATE        BRANCH_CODE     DEPT_CODE       ITEM_CODE       UNIT_CODE       QTY
01/04/2017      KI-01   DP-0001 10001   KG      31.5
01/04/2017      KI-01   DP-0001 10002   KG      22
02/04/2017      KI-01   DP-0001 10001   KG      45
02/04/2017      KI-01   DP-0001 10002   KG      0
03/04/2017      KI-01   DP-0001 10001   KG      72