I have the following function
checkFormat()
{
local funcUserName=$1
if [[ "$funcUserName" != [a-zA-Z0-9][a-zA-Z0-9][a-zA-Z0-9][a-zA-Z0-9] ]];then
echo "1"
else
echo "0"
fi
}
if [[ $string != [a-zA-Z0-9]* ]]
Only returns true if the first character is not [a-zA-Z0-9]
if [[ $string != [a-zA-Z0-9]{5} ]]
Never returns true.
if [[ $string != [a-zA-Z0-9][a-zA-Z0-9][a-zA-Z0-9][a-zA-Z0-9][a-zA-Z0-9] ]]
Returns as I want it to.
Why is this?
The code is to check that a username is 5 characters long and alphanumeric i.e.
Joe12 or 12345 but not %$134.
bash version 4.2.37
I suggest to replace
if [[ $string != [a-zA-Z0-9]{5} ]]
by
if [[ ! $string =~ ^[a-zA-Z0-9]{5}*$ ]]
to match a regex.
Related
I want to check if the letters "d" and "y" are present in string str at the same time in any order.
If I try OR operator | within the regex (d|y) evaluates to true if "d" or "y" are in string, but if use the AND operador & doesn´t work and evaluates to false even
both letters exist in string.
What would be the correct way to check this?
This is what I tested so far
str="good day"
if [[ $str =~ (d|y) ]] # This works for OR operator
if [[ $str =~ (d&y) ]] # doesn´t work for AND operator
then
echo "yes"
else
echo "no"
fi
Thanks in advance.
if [[ $str =~ (d.*y)|(y.*d) ]]; then
or if you don't want to repeat the d and y:
if [[ $str =~ d ]] && [[ $str =~ y ]] ; then
For some reason, the following regular expression match doesn't seem to be working.
string="#Hello world";
[[ "$string" =~ 'ello' ]] && echo "matches";
[[ "$string" =~ 'el.o' ]] && echo "matches";
The first command succeeds (as expected), but the second one does not.
Shouldn't that period be treated by the regular expression as a single character?
Quoting the period causes it to be treated as a literal character, not a regular-expression metacharacter. Best practice if you want to quote the entire regular expression is to do so in a variable, where regular expression matching rules aren't in effect, then expand the parameter unquoted (which is safe to do inside [[ ... ]]).
regex='el.o'
[[ "$string" =~ $regex ]] && echo "matches"
string="#Hello world";
[[ "$string" =~ ello ]] && echo "matches";
[[ "$string" =~ el.o ]] && echo "matches";
Test
$ string="hh elxo fj"
$ [[ "$string" =~ el.o ]] && echo "matches";
matches
I can't get a string with spaces to validate. It works without spaces, but when I include a space in the string it fails. I have googled furiously but can't get it to work.
if [[ $string =~ ^"[A-Za-z ]"$ ]]; then
# true
else
# false
fi
I'm not sure what I'm missing here...
Use a variable to store your regex:
re='^[A-Za-z ]+$'
Then use it as:
[[ "string" =~ $re ]] && echo "matched" || echo "nope"
matched
[[ "string with spaces" =~ $re ]] && echo "matched" || echo "nope"
matched
If you want inline regex then use:
[[ "string with spaces" =~ ^[A-Za-z\ ]+$ ]] && echo "matched" || echo "nope"
matched
Or else use [[:blank:]] property:
[[ "string with spaces" =~ ^[A-Za-z[:blank:]]+$ ]] && echo "matched" || echo "nope"
matched
I should instead use following regex if its always space instead..
if [[ $string =~ ^"[A-Za-z ](\s)"$ ]]; then
# true
else
# false
fi
Cheers :)
the following code works fine on 3.5 bash but not in 4.1
regex='^WORD\-([^(WORD2)][^[:space:]]{1,}$)|(WORD2[[:space:]][^[:space:]]{2,}$)'
if ! [[ $appname =~ $regex ]]
then
printf "no match"
ct_dev_error=$((ct_dev_error+1))
fi
any soliutions? or ideas?
Your regex can be simplified to this:
regex='^WORD-(WORD2[[:space:]][^[:space:]]{2,}|[^[:space:]]+)$'
Test it:
appname='WORD-APP' && [[ $appname =~ $regex ]] && echo "${BASH_REMATCH[0]}"
WORD-APP
appname='WORD-BUD APP' && [[ $appname =~ $regex ]] && echo "${BASH_REMATCH[0]}"
appname='WORD-WORD2 APP' && [[ $appname =~ $regex ]] && echo "${BASH_REMATCH[0]}"
WORD-WORD2 APP
[^(WORD2)] is not actually negating match of WORD2. It is actually a negated character class and it is basically matching a single character that is NOT one of the characters in this list (WORD2).
I don't mean that this question for UNIX only, but I work on Solaris, and I didn't try it on any other OS.
I confused between the extended regular expression:
first:
[[ "str" == ?(str|STR) ]] && echo "matched"
this work correct, but when:
[[ "str str" == ?(str|STR)(.*) ]] && echo "matched"
it doesn't work, does it mean that I can only compare one pattern.
Second:
[[ "str" =~ ?(str|STR) ]] && echo "matched"
I can't use this form here why?, but when:
[[ "str" == (str|STR)? ]] && echo "matched"
it works correctly.
It looks like you are trying to combine
extended globs
with
extended regular expressions. I would say this is A Bad Thing.
$ set '(str|STR)'
$ [[ 'str' =~ $1 ]] && echo matches
matches
$ [[ 'str str' =~ $1 ]] && echo matches
matches