data extraction from xml file

Shell Programming and Scripting
1

I have an of xml file as shown below

<?xml version='1.0' encoding='ASCII' standalone='yes' ?>
<Station Index="10264" >
   <Number Value="237895890" />
   <Position Lat="-29.5" Lon="3.5" />
   <MaxDepth Value="-4939" />
   <VeloLines Count="24">
      <VeloLine Index="0" >
         <Depth Value="0" />
         <Temperature Count="12" >
            2183
            2200
            2253
            2135
            2028
            1859
            1831
            1751
            1740
            1762
            1869
            1996
         </Temperature>
         <Salinity Count="12" >
            3577
            3586
            3583
            3582
            3575
            3580
            3576
            3575
            3566
            3567
            3561
            3569
         </Salinity>
      </VeloLine>
      <VeloLine Index="1" >
         <Depth Value="10" />
         <Temperature Count="12" >
            2155
            2188
            2254
            2128
            2020
            1854
            1810
            1739
            1732
            1749
            1850
            1964
         </Temperature>
         <Salinity Count="12" >
            3576
            3583
            3573
            3581
            3575
            3580
            3575
            3574
            3567
            3567
            3562
            3577
         </Salinity>

The temp gives me the temp for 12 months and salinity for 12 months. the file runs till 752 lines

Question : I want to extract some specific data (depth ,Temp and salinity) from the file i.e temp of 1st month (i.e first value in temp), corresponding salinity in tht month(i.e first value in salinity)

depth     temp    salinity
    0          2183     3577
    10        xxxxxx   xxxxx
    20        yyyyyy   yyyyyy
etc

to a file

My idea : Temp :- is starting from Line 10 for depth 0 and from line 41 for depth to and so on, so 31 lines diff bw them. and similarly for Salinity and similarly for depth - using awk and for loop for data extraction. Will this work ?. or any other ideas to implement this

I have attached the xml file for reference

2 
awk '
BEGIN{print "depth\ttemp\tsalinity"}
/<Depth/ {split($2,a,"\"");depth=a[2]}
/<Temperature/ {getline;temp=$1} 
/<Salinity/ {getline;salinity=$1;printf "%d\t%d\t%d\n",depth,temp,salinity}
' lat_060_lon_003.xml

depth   temp    salinity
0       2183    3577
10      2155    3576
20      2132    3575
30      2103    3574
50      1942    3574
75      1755    3567
100     1671    3561
125     1622    3558
150     1584    3555
200     1478    3543
250     1373    3530
300     1288    3520
400     1109    3498
500     920     3475
600     735     3457
700     576     3443
800     491     3435
900     425     3435
1000    384     3438
1100    350     3444
1200    322     3450
1300    311     3457
1400    303     3462
1500    301     3467
1 Like
3

The program works perfectly fine, I have one more query
if i want to access the first month this works fine, in case i want to get the 2nd or third month then (second or thirs number in Temp ot salinity colum) then is there a way that i can specify an variable along with "getline" which i can change so tht i can decide on the month which i want.

Right now i am using getline 2, 3 or n times to shift the months
awk '

BEGIN{print "depth\ttemp\tsalinity"}
/<Depth/ {split($2,a,"\"");depth=a[2]}
/<Temperature/ {getline;getline;temp=$1} 
/<Salinity/ {getline;getline;salinity=$1;printf "%s\t%d\t%d\n",depth,temp,salinity}
' lat_060_lon_003.xml

is it possible to assin some variable to control how much line it shud jump everytime.

4

Something like this,
you can assign month to variable and loop for getline.

awk -v mon=3 '
BEGIN{print "depth\ttemp\tsalinity"}
/<Depth/ {split($2,a,"\"");depth=a[2]}
/<Temperature/ {for (i=1;i<=mon;i++) {getline};temp=$1}
/<Salinity/ {for (i=1;i<=mon;i++) {getline}salinity=$1;printf "%d\t%d\t%d\n",depth,temp,salinity}
' lat_060_lon_003.xml