Merging the rows in a file using awk - unix

Question

Can somebody explain the meaning of the below script please?
awk -F "," 's != $1 || NR ==1{s=$1;if(p){print p};p=$0;next}
{sub($1,"",$0);p=p""$0;}
END{print p}' file
The file has the following data:
2,"URL","website","aaa.com"
2,"abc","text","some text"
2,"Password","password","12345678"
3,"URL","website","10.0.10.75"
3,"uname","text","some text"
3,"Password","password","password"
3,"ulang","text","some text"
4,"URL","website","192.168.2.110"
4,"Login","login","admin"
4,"Password","password","blah-blah"
and the output is:
2,"URL","website","aaa.com","abc","text","some text",Password","password","12345678"
3,"URL","website","10.0.10.75","uname","text","some text""Password","password","password","ulang","text","some text"

Answer 1

awk has this structure
pattern {action}
for your script, let's analyze the elements, first pattern
s != $1 || NR == 1 # if the variable s is not equal to first field
# or we're operating on first row
first action
s = $1 # assign variable s to first field
if (p) { # if p is not empty, print
print p
}
p = $0 # assign the current line to p variable
next # move to next, skip the rest
next pattern is missing, so the action will apply to all rows
sub($1, "", $0) # same as $1="", will clear the first field
p = ((p "") $0) # concat new line to p
last pattern is special reserved word END, only applied when all rows are consumed (there is counterpart BEGIN that's applied before the file is opened)
END {
print p # print the value of p
}