CODEWITHSUNDEEP
bashgrep
saeed hardan
saeed hardan

Reputation: 485

Check if string contains non digit characters

How can I check if a given string contains non numeric characters, examples : 

x11z returns > 0
x$1 also returns > 0
1111~ also returns > 0

By character I mean everything not between 0-9. I saw similar threads but non of them talks about "non 0-9" except they show if its a-z or A-Z.

Upvotes: 7

Views: 15615

Answers (5)

Rod Klinger
Rod Klinger

Reputation: 31

Most of these suggestions return true if the first character is a digit, but don't find errors within the string. The function below returns true if the entire string is digits, false if any non-digits are detected in the string.

function isdigit () {
   [ $# -eq 1 ] || return 1;
   [[ $1 = *[^0-9]* ]] && return 1
   return 0
}

Upvotes: 3

iruvar
iruvar

Reputation: 23364

Another option, a bash "containment" check

[[ "xf4fgh" = *[^0-9]* ]]
echo $?
0
[[ "1234" = *[^0-9]* ]]
echo $?
1

Upvotes: 1

Salah Eddine Taouririt
Salah Eddine Taouririt

Reputation: 26415

Just by using bash pattern matching:

[[ "$MY_VAR" =~ ^[^0-9]+$ ]] && echo "no digit in $MY_VAR"

Upvotes: 8

jaypal singh
jaypal singh

Reputation: 77105

Something like this:

if [[ "xf44wd" =~ [0-9]+ ]]; then
    echo "contains $?"
    else
    echo "does no contains $?"
fi

or

if [[ ! "xf44wd" =~ [0-9]+ ]]; then
    echo "does not contains $?"
    else
    echo "contains $?"
fi

Upvotes: 3

squiguy
squiguy

Reputation: 33370

Just use a negated character class:

grep [^0-9]

This will match any non-numeric character, and not strings composed of only digits.

Upvotes: 11

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