Condition regex error
Clash Royale CLAN TAG#URR8PPP
up vote
12
down vote
favorite
2
string=123456
if [ $string == 123456 ]; then
echo 123
fi
This works fine, but if I change == to =~ I get this error:
./test: line 3: [: =~: binary operator expected
bash shell-script
asked Oct 22 '17 at 18:25
Lumify
1217
add a comment |Â
up vote
12
down vote
favorite
2
string=123456
if [ $string == 123456 ]; then
echo 123
fi
This works fine, but if I change == to =~ I get this error:
./test: line 3: [: =~: binary operator expected
bash shell-script
asked Oct 22 '17 at 18:25
Lumify
1217
The use of=~is in this case wrong.=~compares the patter (left side of the assignment) with a regular expresionregexon the right side of the assinment. A regular expression in its simplest form is passed like'[0-9][0-9]'
– Valentin B
Oct 22 '17 at 18:42
8
@val0x00ff but123456is a valid RE
– roaima
Oct 22 '17 at 19:01
@roaima agreed, however regex is known for its engine, back-referencing, character-set, meta chars denoting starting of a string, ending of a string etc.
– Valentin B
Oct 22 '17 at 19:11
add a comment |Â
up vote
12
down vote
favorite
2
up vote
12
down vote
favorite
2
2
string=123456
if [ $string == 123456 ]; then
echo 123
fi
This works fine, but if I change == to =~ I get this error:
./test: line 3: [: =~: binary operator expected
bash shell-script
asked Oct 22 '17 at 18:25
Lumify
1217
string=123456
if [ $string == 123456 ]; then
echo 123
fi
This works fine, but if I change == to =~ I get this error:
./test: line 3: [: =~: binary operator expected
bash shell-script
asked Oct 22 '17 at 18:25
Lumify
1217
asked Oct 22 '17 at 18:25
Lumify
1217
asked Oct 22 '17 at 18:25
Lumify
1217
asked Oct 22 '17 at 18:25
Lumify
1217
1217
The use of=~is in this case wrong.=~compares the patter (left side of the assignment) with a regular expresionregexon the right side of the assinment. A regular expression in its simplest form is passed like'[0-9][0-9]'
– Valentin B
Oct 22 '17 at 18:42
8
@val0x00ff but123456is a valid RE
– roaima
Oct 22 '17 at 19:01
@roaima agreed, however regex is known for its engine, back-referencing, character-set, meta chars denoting starting of a string, ending of a string etc.
– Valentin B
Oct 22 '17 at 19:11
add a comment |Â
The use of=~is in this case wrong.=~compares the patter (left side of the assignment) with a regular expresionregexon the right side of the assinment. A regular expression in its simplest form is passed like'[0-9][0-9]'
– Valentin B
Oct 22 '17 at 18:42
8
@val0x00ff but123456is a valid RE
– roaima
Oct 22 '17 at 19:01
@roaima agreed, however regex is known for its engine, back-referencing, character-set, meta chars denoting starting of a string, ending of a string etc.
– Valentin B
Oct 22 '17 at 19:11
The use of
=~ is in this case wrong. =~ compares the patter (left side of the assignment) with a regular expresion regex on the right side of the assinment. A regular expression in its simplest form is passed like '[0-9][0-9]'– Valentin B
Oct 22 '17 at 18:42
The use of
=~ is in this case wrong. =~ compares the patter (left side of the assignment) with a regular expresion regex on the right side of the assinment. A regular expression in its simplest form is passed like '[0-9][0-9]'– Valentin B
Oct 22 '17 at 18:42
8
8
@val0x00ff but
123456 is a valid RE– roaima
Oct 22 '17 at 19:01
@val0x00ff but
123456 is a valid RE– roaima
Oct 22 '17 at 19:01
@roaima agreed, however regex is known for its engine, back-referencing, character-set, meta chars denoting starting of a string, ending of a string etc.
– Valentin B
Oct 22 '17 at 19:11
@roaima agreed, however regex is known for its engine, back-referencing, character-set, meta chars denoting starting of a string, ending of a string etc.
– Valentin B
Oct 22 '17 at 19:11
add a comment |Â
1 Answer
1
active
oldest
votes
up vote
24
down vote
accepted
Bash's regex matching works only within double square brackets [[ ... ]]:
string=123456
if [[ "$string" =~ 123456 ]]; then echo 123; fi
123
edited Oct 22 '17 at 19:54
Kusalananda
105k14209326
answered Oct 22 '17 at 18:30
RomanPerekhrest
22.5k12145
@Kusalananda: Regarding the edit, the quotes are not required on the left hand side of a double bracket expression[[ ... ]], since no word splitting or pathname expansion occurs there. They are only needed when using single brackets[ ... ](both sides) and on the right hand of the double bracket expression.
– user000001
Oct 23 '17 at 11:21
@user000001 while you're correct, it's much better just to quote all variables by reflex unless there's a necessity not to. It's a much safer habit.
– Joe
Oct 27 '17 at 20:00
@Joe: Agreed, when in doubt, quote... I only mentioned this because it was an edit to an already correct answer. Had it been there from the first revision I would not have commented on this.
– user000001
Oct 28 '17 at 13:06
add a comment |Â
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
24
down vote
accepted
Bash's regex matching works only within double square brackets [[ ... ]]:
string=123456
if [[ "$string" =~ 123456 ]]; then echo 123; fi
123
edited Oct 22 '17 at 19:54
Kusalananda
105k14209326
answered Oct 22 '17 at 18:30
RomanPerekhrest
22.5k12145
@Kusalananda: Regarding the edit, the quotes are not required on the left hand side of a double bracket expression[[ ... ]], since no word splitting or pathname expansion occurs there. They are only needed when using single brackets[ ... ](both sides) and on the right hand of the double bracket expression.
– user000001
Oct 23 '17 at 11:21
@user000001 while you're correct, it's much better just to quote all variables by reflex unless there's a necessity not to. It's a much safer habit.
– Joe
Oct 27 '17 at 20:00
@Joe: Agreed, when in doubt, quote... I only mentioned this because it was an edit to an already correct answer. Had it been there from the first revision I would not have commented on this.
– user000001
Oct 28 '17 at 13:06
add a comment |Â
up vote
24
down vote
accepted
Bash's regex matching works only within double square brackets [[ ... ]]:
string=123456
if [[ "$string" =~ 123456 ]]; then echo 123; fi
123
edited Oct 22 '17 at 19:54
Kusalananda
105k14209326
answered Oct 22 '17 at 18:30
RomanPerekhrest
22.5k12145
@Kusalananda: Regarding the edit, the quotes are not required on the left hand side of a double bracket expression[[ ... ]], since no word splitting or pathname expansion occurs there. They are only needed when using single brackets[ ... ](both sides) and on the right hand of the double bracket expression.
– user000001
Oct 23 '17 at 11:21
@user000001 while you're correct, it's much better just to quote all variables by reflex unless there's a necessity not to. It's a much safer habit.
– Joe
Oct 27 '17 at 20:00
@Joe: Agreed, when in doubt, quote... I only mentioned this because it was an edit to an already correct answer. Had it been there from the first revision I would not have commented on this.
– user000001
Oct 28 '17 at 13:06
add a comment |Â
up vote
24
down vote
accepted
up vote
24
down vote
accepted
Bash's regex matching works only within double square brackets [[ ... ]]:
string=123456
if [[ "$string" =~ 123456 ]]; then echo 123; fi
123
edited Oct 22 '17 at 19:54
Kusalananda
105k14209326
answered Oct 22 '17 at 18:30
RomanPerekhrest
22.5k12145
Bash's regex matching works only within double square brackets [[ ... ]]:
string=123456
if [[ "$string" =~ 123456 ]]; then echo 123; fi
123
edited Oct 22 '17 at 19:54
Kusalananda
105k14209326
answered Oct 22 '17 at 18:30
RomanPerekhrest
22.5k12145
edited Oct 22 '17 at 19:54
Kusalananda
105k14209326
edited Oct 22 '17 at 19:54
Kusalananda
105k14209326
edited Oct 22 '17 at 19:54
Kusalananda
105k14209326
105k14209326
answered Oct 22 '17 at 18:30
RomanPerekhrest
22.5k12145
answered Oct 22 '17 at 18:30
RomanPerekhrest
22.5k12145
answered Oct 22 '17 at 18:30
RomanPerekhrest
22.5k12145
22.5k12145
@Kusalananda: Regarding the edit, the quotes are not required on the left hand side of a double bracket expression[[ ... ]], since no word splitting or pathname expansion occurs there. They are only needed when using single brackets[ ... ](both sides) and on the right hand of the double bracket expression.
– user000001
Oct 23 '17 at 11:21
@user000001 while you're correct, it's much better just to quote all variables by reflex unless there's a necessity not to. It's a much safer habit.
– Joe
Oct 27 '17 at 20:00
@Joe: Agreed, when in doubt, quote... I only mentioned this because it was an edit to an already correct answer. Had it been there from the first revision I would not have commented on this.
– user000001
Oct 28 '17 at 13:06
add a comment |Â
@Kusalananda: Regarding the edit, the quotes are not required on the left hand side of a double bracket expression[[ ... ]], since no word splitting or pathname expansion occurs there. They are only needed when using single brackets[ ... ](both sides) and on the right hand of the double bracket expression.
– user000001
Oct 23 '17 at 11:21
@user000001 while you're correct, it's much better just to quote all variables by reflex unless there's a necessity not to. It's a much safer habit.
– Joe
Oct 27 '17 at 20:00
@Joe: Agreed, when in doubt, quote... I only mentioned this because it was an edit to an already correct answer. Had it been there from the first revision I would not have commented on this.
– user000001
Oct 28 '17 at 13:06
@Kusalananda: Regarding the edit, the quotes are not required on the left hand side of a double bracket expression
[[ ... ]], since no word splitting or pathname expansion occurs there. They are only needed when using single brackets [ ... ] (both sides) and on the right hand of the double bracket expression.– user000001
Oct 23 '17 at 11:21
@Kusalananda: Regarding the edit, the quotes are not required on the left hand side of a double bracket expression
[[ ... ]], since no word splitting or pathname expansion occurs there. They are only needed when using single brackets [ ... ] (both sides) and on the right hand of the double bracket expression.– user000001
Oct 23 '17 at 11:21
@user000001 while you're correct, it's much better just to quote all variables by reflex unless there's a necessity not to. It's a much safer habit.
– Joe
Oct 27 '17 at 20:00
@user000001 while you're correct, it's much better just to quote all variables by reflex unless there's a necessity not to. It's a much safer habit.
– Joe
Oct 27 '17 at 20:00
@Joe: Agreed, when in doubt, quote... I only mentioned this because it was an edit to an already correct answer. Had it been there from the first revision I would not have commented on this.
– user000001
Oct 28 '17 at 13:06
@Joe: Agreed, when in doubt, quote... I only mentioned this because it was an edit to an already correct answer. Had it been there from the first revision I would not have commented on this.
– user000001
Oct 28 '17 at 13:06
add a comment |Â
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The use of
=~is in this case wrong.=~compares the patter (left side of the assignment) with a regular expresionregexon the right side of the assinment. A regular expression in its simplest form is passed like'[0-9][0-9]'– Valentin B
Oct 22 '17 at 18:42
8
@val0x00ff but
123456is a valid RE– roaima
Oct 22 '17 at 19:01
@roaima agreed, however regex is known for its engine, back-referencing, character-set, meta chars denoting starting of a string, ending of a string etc.
– Valentin B
Oct 22 '17 at 19:11