LinuxQuestions.org - pattern match problem

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- - pattern match problem (https://www.linuxquestions.org/questions/programming-9/pattern-match-problem-4175462582/)

pattern match problem

if i have to do pattern match for file name with digit alphanumeric value like this

Code:

File_1234.csv



File_12sd45rg.csv

i am using this File_[0-9a-zA-Z]*.csv
and File_[0-9]*.csv for digit pattern match.

when i am doing pattern match for the digit then both alphanumeric match
and digit match is coming.
where only digit match should should come.
If usinng [:digit:] then it is not working.

Code:

the part of code which i am using is like this





i=0

len=${#arr[@]}

echo $len



shopt -s extglob



pattern=*[0-9]*.*

pattern1=*[0-9]*_[0-9]*.*

pattern2=*[a-zA-z0-9]*.*

pattern3=File_[0-9]*_[0-9]*.csv

pattern4=File_[a-zA-Z]*_[a-zA-Z]*.csv

pattern5=File_[a-zA-Z0-9]*_[a-zA-Z0-9]*.csv

pattern6=File_[0-9]*[a-zA-Z]*.csv



while [ $len -gt $i ]

do

  case ${arr[$i]} in

  $pattern) echo "pattern %N% match" ;;

  esac

  case ${arr[$i]} in

  $pattern1) echo "pattern %N%_%N% match" ;;

  esac

  case ${arr[$i]} in

  $pattern2) echo "pattern %x% match" ;;

  esac

In that code fragment, you set i=0 but fail to increment it, so it looks like an infinite loop...

As to your specific question, consider this:

Code:

$ cat ramsvi

#!/bin/bash

arr=(File_1234.csv File_12sd45rg.csv)



len=${#arr[@]}

echo $len



shopt -s extglob



pattern0=*[0-9]*.*

pattern1=*[0-9]*_[0-9]*.*

pattern2=*[a-zA-z0-9]*.*

pattern3=File_[0-9]*_[0-9]*.csv

pattern4=File_[a-zA-Z]*_[a-zA-Z]*.csv

pattern5=File_[a-zA-Z0-9]*_[a-zA-Z0-9]*.csv

pattern6=File_[0-9]*[a-zA-Z]*.csv



for ((i=0; i<len; ++i))

do

  echo ${arr[${i}]}

  case ${arr[${i}]} in

    (${pattern0}) echo "pattern0 match" ;;&

    (${pattern1}) echo "pattern1 match" ;;&

    (${pattern2}) echo "pattern2 match" ;;&

    (${pattern3}) echo "pattern3 match" ;;&

    (${pattern4}) echo "pattern4 match" ;;&

    (${pattern5}) echo "pattern5 match" ;;&

    (${pattern6}) echo "pattern6 match" ;;

    (*) echo "No match.";;

  esac

  i=$((++${i}))

done

$ bash ramsavi

2

File_1234.csv

pattern0 match

pattern2 match

No match.

File_12sd45rg.csv

pattern0 match

pattern2 match

pattern6 match

So, your question is "Why does pattern2 match in the second case?" But "*" in a bash pattern means "match anything," so *[0-9]*.* means "match anything containing a number anywhere before a dot" which always matches your file names.

Anyhow, why are you using a shell script for this task? There are several other languages that could, I think, be better used for this problem. (e.g., sed, gawk, grep, etc.)

I think this is just a duplicate of this thread.