awk from file using echo and output to file - bash

Question

A.txt contains:
/*333*/
asdfasdfadfg
sadfasdfasgadas
###
/*555*/
hfawehfihohawe
aweihfiwahif
aiwehfwwh
###
/*777*/
jawejfiawjia
ajwiejfjeiie
eiuehhawefjj
###
B.txt contains:
555
777
I want to create the loop, for each string found in B.txt, then output the '/*'[the string] until right before the first '###' met to each own file (the string name is also used as file name).
So based on the sample above, the result should be :
555.txt, which contains:
/*555*/
hfawehfihohawe
aweihfiwahif
aiwehfwwh
and 777.txt, which contains:
/*777*/
jawejfiawjia
ajwiejfjeiie
eiuehhawefjj
I tried this script but it outputs nothing:
for i in `cat B.txt`; do echo $i | awk '/{print "/*"$1}/{flag=1} /###/{flag=0} flag' A.txt > $i.txt; done
Thank you in advance

Answer 1

With your shown samples, please try following awk code. Written and tested in GNU awk should work in any awk.
awk '
FNR==NR{
if($0~/^\/\*/){
line=$0
gsub(/^\/\*|\*\/$/,"",line)
arr[++count]=$0
arr1[line]=count
next
}
arr[count]=(arr[count]?arr[count] ORS:"") $0
next
}
($0 in arr1){
outputFile=$0".txt"
print arr[arr1[$0]] >> (outputFile)
close(outputFile)
}
' file1 file2
Explanation: Adding detailed explanation for above code.
awk ' ##Starting awk program from here.
FNR==NR{ ##Checking condition FNR==NR which will be TRUE when file1 is being read.
if($0~/^\/\*/){ ##Checking condition if current line starts with /* then do following.
line=$0 ##Setting $0 to line variable here.
gsub(/^\/\*|\*\/$/,"",line) ##using gsub to globally substitute starting /* and ending */ with NULL in line here.
arr[++count]=$0 ##Creating arr with index of ++count and value is $0.
arr1[line]=count ##Creating arr1 with index of line and value of count.
next ##next will skip all further statements from here.
}
arr[count]=(arr[count]?arr[count] ORS:"") $0 ##Creating arr with index of count and keep appending values of same count values with current line value.
next ##next will skip all further statements from here.
}
($0 in arr1){ ##checking if current line is present in arr1 then do following.
outputFile=$0".txt" ##Creating outputFile with current line .txt value here.
print arr[arr1[$0]] >> (outputFile) ##Printing arr value with index of arr1[$0] to outputFile.
close(outputFile) ##Closing outputFile in backend to avoid too many opened files error.
}
' file1 file2 ##Mentioning Input_file names here.

Answer 2

Making a few alterations to your code provides the desired outcome with the example data provided:
while read -r f
do
awk -v var="/[*]$f[*]/" '$0 ~ var {flag=1} /###/{flag=0} flag' A.txt > "$f".txt
done < B.txt
cat 555.txt
/*555*/
hfawehfihohawe
aweihfiwahif
aiwehfwwh
cat 777.txt
jawejfiawjia
ajwiejfjeiie
eiuehhawefjj
Does this solve your problem?

Answer 3

Here is another awk solution for this:
awk '
FNR == NR {
map["/*" $0 "*/"] = $0
next
}
$0 in map {
fn = map[$0] ".txt"
}
/^###$/ {
close(fn)
fn = ""
}
fn {print > fn}' B.txt A.txt