bash - Is there way of distinguishing between characters and numbers? -

i've got bash script, interprets incoming datum. hoping if there way of bash realizing whether it's combination of letters example hi, bye bye or numbers 123451.

what snippet of code like??

awk_variables=`echo "$line" | awk -f, '{print $1, $4, $5, $7, $10 }'` awk_variables_value_array=($awk_variables)          #turns contents of 'awk_variables' array 'awk_variables_value_array' 

^ part of code reading ($)line csv file. it's here datum 'hello' or numbers if thats case don't want read it. $4 have letters when gets read.

q: script if able distinguish datum letters , numbers?

---

ideally: alternative approach if bit of code count how many parameters there in given ($)line. if parameters not equal x amount, not read it, , skip next line. q: script like?

to split line (here, $line) array (here, ${array[@]}) using , delimiter:

ifs=, read -r -a array <<<"$line" 

to see how many values put array:

${#array[@]} 

to see if specific element consists of numbers:

! [[ ${array[4]} =~ [^0-9] ]] 

(the ! go inside [[...]]. adjust character class if want include negative numbers, decimal points, etc.)