Shell Programming and Scripting

<CARS>
 <AUDI>
  <Speed="45"/>
  <speed="55"/>
  <speed="75"/>
  <speed="95"/>
 </AUDI>
 
 <BMW>
  <Speed="30"/>
  <speed="75"/>
  <speed="120"/>
  <speed="135"/>
 </BMW>
</CARS>

$ awk '/<Speed|<speed/ && gsub(/.*="|"\/>/,x)' file
45
55
75
95
30
75
120
135

$ grep -Po -i '(?<=<Speed=").*(?="/>)' file
45
55
75
95
30
75
120
135

awk '/[0-9]/ {print $0}' file_name | sed 's/[a-zA-Z]//g;s/[[:punct:]]//g'

  45
  55
  75
  95
  30
  75
  120
  135

#!/bin/bash

flag=0
while read line
do
        [[ "$line" =~ "<BMW>" ]] && flag=1
        [[ "$line" =~ "</BMW>" ]] && flag=0
        if [ $flag -eq 1 ] && [[ "$line" =~ [Ss]peed ]]
        then
                (( ++c ))
                line="${line##*=\"}"
                S[$c]="${line%%\"*}"
        fi
done < file.xml

for k in "${S[@]}"
do
        echo "$k"
done

$ cat test.sh
#!/bin/bash

# Parse speed  values between tag and write output to temporary file
  awk '/<BMW>/,/<\/BMW>/{if(/<Speed|<speed/){gsub(/.*="|"\/>/,x);print}}' file.xml >test.tmp

# Create array
  arr=( $( < test.tmp  ) )

# OR you can use cut command for specific column into an Array instead of entire line may be useful in future
# arr=( $( < <(cut -f1 test.tmp )  ) )

# delete temporary file created using awk
  rm -f test.tmp

# Print Array Elements
  for i in $(seq 0 $((${#arr[@]} - 1)))
  do
    echo ${arr[$i]}
  done

# OR
# for i in ${arr[@]}
# do
#    echo $i
# done

$ bash test.sh
30
75
120
135

awk '/\<\/BMW\>/  {f=0} (f ~ 1) {gsub(/[[:alpha:]]/,X,$0) gsub(/[[:punct:]]/,Y,$0); {print $0}} /\<BMW\>/ {f=1}' check_all_BMW_values

  30
  75
  120
  135