extract info from a tag using awk - awk

Question

I have multi columns file and i want to extract some info in column 71.
I want to extract using tags which the value can be anything, for example i want to just extract AC=* ; AF=* , where the value can be anything .
I found similar question and gave it a try but it didn't work
Extract columns with values matching a specific pattern
Column 71 looks like this:
AC=14511;AC_AFR=382;AC_AMR=1177;AC_Adj=14343;AC_EAS=5;AC_FIN=427;AC_Het=11813;AC_Hom=1265;AC_NFE=11027;AC_OTH=97;AC_SAS=1228;AF=0.137;AN=106198;AN_AFR=8190;AN_AMR=10424;AN_Adj=99264;AN_EAS=7068;AN_FIN=6414;AN_NFE=51090;AN_OTH=658;AN_SAS=15420;BaseQRankSum=1.73;ClippingRankSum=-1.460e-01;DB;DP=1268322;FS=0.000;GQ_MEAN=190.24;GQ_STDDEV=319.67;Het_AFR=358;Het_AMR=1049;Het_EAS=5;Het_FIN=399;Het_NFE=8799;Het_OTH=83;Het_SAS=1120;Hom_AFR=12;Hom_AMR=64;Hom_EAS=0;Hom_FIN=14;Hom_NFE=1114;Hom_OTH=7;Hom_SAS=54;InbreedingCoeff=0.0478;MQ=60.00;MQ0=0;MQRankSum=0.037;NCC=270;POSITIVE_TRAIN_SITE;QD=21.41;ReadPosRankSum=0.212;VQSLOD=4.79;culprit=MQ;DP_HIST=30|3209|1539|1494|30007|7938|4130|2038|1310|612|334|185|97|60|31|25|9|11|7|33,0|66|339|1048|2096|2665|2626|1832|1210|584|323|179|89|54|31|22|7|9|4|15;GQ_HIST=84|66|56|82|3299|568|617|403|250|319|436|310|28566|2937|827|834|451|186|217|12591,15|15|13|16|25|11|22|28|18|38|52|31|65|76|39|83|93|65|97|12397;CSQ=T|ENSG00000186868|ENST00000334239|Transcript|intron_variant||||||rs754512|1||1|MAPT|HGNC|6893|protein_coding||CCDS11502.1|ENSP00000334886|TAU_HUMAN|B4DSE3_HUMAN|UPI0000000C16||||2/8||ENST00000334239.8:c.134-94A>T||T:0.1171|||||||||15792962||||||||,T|ENSG00000186868|ENST00000570299|Transcript|intron_variant&non_coding_transcript_variant||||||rs754512|1||1|MAPT|HGNC|6893|processed_transcript||||||||||2/6||ENST00000570299.1:n.262-94A>T||T:0.1171|||||||||15792962||||||||,T|ENSG00000186868|ENST00000340799|Transcript|intron_variant||||||rs754512|1||1|MAPT|HGNC|6893|protein_coding||CCDS45716.1|ENSP00000340438|TAU_HUMAN||UPI000004EEE6||||3/10||ENST00000340799.5:c.221-94A>T||T:0.1171|||||||||15792962||||||||,T|ENSG00000186868|ENST00000262410|Transcript|intron_variant||||||rs754512|1||1|MAPT|HGNC|6893|protein_coding||CCDS11501.1|ENSP00000262410|TAU_HUMAN||UPI0000EE80B7||||4/13||ENST00000262410.5:c.308-94A>T||T:0.1171|||||||||15792962||||||||,T|ENSG00000186868|ENST00000446361|Transcript|intron_variant||||||rs754512|1||1|MAPT|HGNC|6893|protein_coding||CCDS11500.1|ENSP00000408975|TAU_HUMAN||UPI000004EEE5||||2/9||ENST00000446361.3:c.134-94A>T||T:0.1171|||||||||15792962||||||||,T|ENSG00000186868|ENST00000574436|Transcript|intron_variant||||||rs754512|1||1|MAPT|HGNC|6893|protein_coding||CCDS11499.1|ENSP00000460965|TAU_HUMAN||UPI000002D754||||3/10||ENST00000574436.1:c.308-94A>T||T:0.1171|||||||||15792962||||||||,T|ENSG00000186868|ENST00000571987|Transcript|intron_variant||||||rs754512|1||1|MAPT|HGNC|6893|protein_coding||CCDS11501.1|ENSP00000458742|TAU_HUMAN||UPI0000EE80B7||||3/12||ENST00000571987.1:c.308-94A>T||T:0.1171|||||||||15792962||||||||,T|ENSG00000186868|ENST00000415613|Transcript|intron_variant||||||rs754512|1||1|MAPT|HGNC|6893|protein_coding||CCDS45715.1|ENSP00000410838|TAU_HUMAN||UPI0001AE66E9||||3/13||ENST00000415613.2:c.308-94A>T||T:0.1171|||||||||15792962||||||||,T|ENSG00000186868|ENST00000571311|Transcript|intron_variant&NMD_transcript_variant||||||rs754512|1||1|MAPT|HGNC|6893|nonsense_mediated_decay|||ENSP00000460048||I3L2Z2_HUMAN|UPI00025A2E6E||||4/4||ENST00000571311.1:c.*176-94A>T||T:0.1171|||||||||15792962||||||||,T|ENSG00000186868|ENST00000535772|Transcript|intron_variant||||||rs754512|1||1|MAPT|HGNC|6893|protein_coding||CCDS56033.1|ENSP00000443028|TAU_HUMAN|B4DSE3_HUMAN|UPI000004EEE4||||4/10||ENST00000535772.1:c.308-94A>T||T:0.1171|||||||||15792962||||||||,T|ENSG00000186868|ENST00000576518|Transcript|stop_gained|5499|7|3|K/*|Aag/Tag|rs754512|1||1|MAPT|HGNC|6893|protein_coding|||ENSP00000458621||I3L170_HUMAN&B4DSE3_HUMAN|UPI0001639A7C|||1/7|||ENST00000576518.1:c.7A>T|ENSP00000458621.1:p.Lys3Ter|T:0.1171|||||||||15792962|||||POSITION:0.00682261208576998&ANN_ORF:-255.6993&MAX_ORF:-255.6993|PHYLOCSF_WEAK|ANC_ALLELE|LC,T|ENSG00000186868|ENST00000420682|Transcript|intron_variant||||||rs754512|1||1|MAPT|HGNC|6893|protein_coding||CCDS45716.1|ENSP00000413056|TAU_HUMAN||UPI000004EEE6||||2/9||ENST00000420682.2:c.221-94A>T||T:0.1171|||||||||15792962||||||||,T|ENSG00000186868|ENST00000572440|Transcript|non_coding_transcript_exon_variant&non_coding_transcript_variant|2790|||||rs754512|1||1|MAPT|HGNC|6893|retained_intron|||||||||1/1|||ENST00000572440.1:n.2790A>T||T:0.1171|||||||||15792962||||||||,T|ENSG00000186868|ENST00000351559|Transcript|intron_variant||||||rs754512|1||1|MAPT|HGNC|6893|protein_coding||CCDS11499.1|ENSP00000303214|TAU_HUMAN||UPI000002D754||||4/11||ENST00000351559.5:c.308-94A>T||T:0.1171|||||||||15792962||||||||,T|ENSG00000186868|ENST00000344290|Transcript|intron_variant||||||rs754512|1||1|MAPT|HGNC|6893|protein_coding|YES|CCDS45715.1|ENSP00000340820|TAU_HUMAN||UPI0001AE66E9||||4/14||ENST00000344290.5:c.308-94A>T||T:0.1171|||||||||15792962||||||||,T|ENSG00000186868|ENST00000347967|Transcript|intron_variant||||||rs754512|1||1|MAPT|HGNC|6893|protein_coding|||ENSP00000302706|TAU_HUMAN|B4DSE3_HUMAN|UPI0000173D91||||4/10||ENST00000347967.5:c.32-100A>T||T:0.1171|||||||||15792962||||||||,T|ENSG00000186868|ENST00000431008|Transcript|intron_variant||||||rs754512|1||1|MAPT|HGNC|6893|protein_coding||CCDS56033.1|ENSP00000389250|TAU_HUMAN|B4DSE3_HUMAN|UPI000004EEE4||||3/9||ENST00000431008.3:c.308-94A>T||T:0.1171|||||||||15792962||||||||
The code that i tried:
awk '{
for (i = 1; i <= NF; i++) {
if ($i ~ /AC|AF/) {
printf "%s %s ", $i, $(i + 1)
}
}
print ""
}'
I keep getting syntax error.
output wanted :
AC=14511;AF=0.137

Answer 1

Whenever you have name=value pairs, it's usually simplest to first create an array that maps names to values (n2v[] below) and then you can just access the values by their names.
$ cat file
AC=1;AC_AFR=2;AF=3 AC=4;AC_AFR=5;AF=6
$ cat tst.awk
{
delete n2v
split($2,tmp,/[;=]/)
for (i=1; i in tmp; i+=2) {
n2v[tmp[i]] = tmp[i+1]
}
prt("AC")
prt("AF")
}
function prt(name) { print name, "=", n2v[name] }
$ awk -f tst.awk file
AC = 4
AF = 6
Just change $2 to $71 for your real input.

Answer 2

Something like this should do it (in Gnu awk due to switch):
$ awk '{split($71,a,";");for(i in a )if(a[i]~/^AF/) print a[i]}' foo
AF=0.137
You split the field $71 by ;s, loop thru the array you split to looking for desired match. For multiple matches use switch:
$ awk '{
split($0,a,";");
for(i in a )
switch(a[i]) {
case /^AF=/:
b=b a[i] OFS;
break;
case /^AC=/:
b=b a[i] OFS;
break
}
sub(/.$/,"\n",b);
printf b
}' foo
AC=14511 AF=0.137
EDIT: Now it buffers output to a variable and prints it in the end. You can control the separator with OFS.