Shell Programming and Scripting

~ cat input.file
 random text
 Fe  1.33 23.23 3.33
 C  21.03 23.23 3.33
 Cu  0.00  0.00 0.00
 random text
%block ChemicalSpeciesLabel
 1 26  Fe
 3  6  C
 6 29  Cu
%endblock ChemicalSpeciesLabel
 random text

~ cat output.file
 26  1.33 23.23 3.33
 6  21.03 23.23 3.33
 29  0.00  0.00 0.00

~ cat output.file
 26  1.33 23.23 3.33
 6  21.03 23.23 3.33
 6u  0.00  0.00 0.00

 awk '{ printf("o%-2s\n",$1) }' input.file > input.file.1

 sed '/%block.*ChemicalSpeciesLabel/I,/endblock.*ChemicalSpeciesLabel/I!d;/ChemicalSpeciesLabel/Id' input.file |awk '{printf("o%-3s %7s\n", $3, $2)}' > rules

 for file in $(ls -1 input.file.1)
  do
    awk 'NR==FNR {a[$1]=$2;next} {for ( i in a) gsub(i,a[i])}1' rules $file >temp.file
  done

awk '{
   if ($1 ~ "^[A-Z]([a-z])?") {
      f=$1
      $1=""
      x[f]=$0
   }
   if ($NF ~ "^[A-Z]([a-z])?$") {
      l=$NF
      $NF=""
      y[l]=$(NF-1)
   }
} END {for (i in x) print y[i], x[i]}' inputfile

awk ' 
#{printf("FNR=%d, NR=%d, t=%d, $0=%s\n", FNR, NR, t, $0)}
FNR==NR && /^%block/ {
        # Following lines contain translation table.
        t = 1
        next 
}     
FNR==NR && /^%endblock/ {
        # We have found the end of the translation table.
        t = 0
        next
}
t {     # Add entry to tranlsation table.
        tt[$3] = $2
        next
}
FNR!=NR && $1 in tt {
        # This is the second time through the file and we have found a line
        # with its 1st field set to a value in our translation table.
        # Translate the value and print the line.
        # Note that we use sub() here rather than $1 = tt[$1] to keep the
        # original spacing from the input lines.
        sub($1, tt[$1])
        print
}' input.file input.file > output.file