awk from file using echo and output to file-CodePudding

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

CodePudding user response：

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?

CodePudding user response：

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.