I've been trying to write bash script, that validates user input with given rules: length > 8, at least one digit, and at least one of these: [#, #, $]
So regex for that is this:
((?=.*\d)(?=.*[##$%&*+-=]).{8,})
I've tried this, but with no result:
result=$(echo $1 | egrep "((?=.*\d)(?=.*[##$%&*+-=]).{8,})")
echo $result
with $1 being input parameter. Also, I'd like to wrap it in IF clause, but echo never outputs anything. What am i doing wrong?
This might help:
[[ ${#1} -ge 8 && $1 =~ [0-9] && $1 =~ [##$] ]] && result="$1"
or with three grep:
result=$(grep -E '.{8}' <<< "$1" | grep '[0-9]' | grep '[##$]')
Related
I had problem with cut variables from string in " quotes. I have some scripts to write for my sys classes, I had a problem with a script in which I had to read input from the user in the form of (a="var1", b="var2")
I tried the code below
#!/bin/bash
read input
a=$($input | cut -d '"' -f3)
echo $a
it returns me a error "not found a command" on line 3 I tried to double brackets like
a=$(($input | cut -d '"' -f3)
but it's still wrong.
In a comment the OP gave a working answer (should post it as an answer):
#!/bin/bash
read input
a=$(echo $input | cut -d '"' -f2)
b=$(echo $input | cut -d '"' -f4)
echo sum: $(( a + b))
echo difference: $(( a - b))
This will work for user input that is exactly like a="8", b="5".
Never trust input.
You might want to add the check
if [[ ${input} =~ ^[a-z]+=\"[0-9]+\",\ [a-z]+=\"[0-9]+\"$ ]]; then
echo "Use your code"
else
echo "Incorrect input"
fi
And when you add a check, you might want to execute the input (after replacing the comma with a semicolon).
input='testa="8", testb="5"'
if [[ ${input} =~ ^[a-z]+=\"[0-9]+\",\ [a-z]+=\"[0-9]+\"$ ]];
then
eval $(tr "," ";" <<< ${input})
set | grep -E "^test[ab]="
else
echo no
fi
EDIT:
#PesaThe commented correctly about BASH_REMATCH:
When you use bash and a test on the input you can use
if [[ ${input} =~ ^[a-z]+=\"([0-9]+)\",\ [a-z]+=\"([0-9])+\"$ ]];
then
a="${BASH_REMATCH[1]}"
b="${BASH_REMATCH[2]}"
fi
To extract the digit 1 from a string "var1" you would use a Bash substring replacement most likely:
$ s="var1"
$ echo "${s//[^0-9]/}"
1
Or,
$ a="${s//[^0-9]/}"
$ echo "$a"
1
This works by replacing any non digits in a string with nothing. Which works in your example with a single number field in the string but may not be what you need if you have multiple number fields:
$ s2="1 and a 2 and 3"
$ echo "${s2//[^0-9]/}"
123
In this case, you would use sed or grep awk or a Bash regex to capture the individual number fields and keep them distinct:
$ echo "$s2" | grep -o -E '[[:digit:]]+'
1
2
3
I have the next two regex in Bash:
1.^[-a-zA-Z0-9\,\.\;\:]*$
2.^[]a-zA-Z0-9\,\.\;\:]*$
The first matches when the string contains a "-" and the other values.
The second when contains a "]".
I put this values at the beginning of my regex because I can't scape them.
How I can get match the two values at the same time?
You can also place the - at the end of the bracket expression, since a range must be closed on both ends.
^[]a-zA-Z0-9,.;:-]*$
You don't have to escape any of the other characters, either. Colons, semicolons, and commas have no special meaning in any part of a regular expression, and while a period loses its special meaning inside a bracket expression.
Basically you can use this:
grep -E '^.*\-.*\[|\[.*\-.*$'
It matches either a - followed by zero or more arbitrary chars and a [ or a [ followed by zero or more chars and a -
However since you don't accept arbitrary chars, you need to change it to:
grep -E '^[a-zA-Z0-9,.;:]*\-[a-zA-Z0-9,.;:]*\[|\[[a-zA-Z0-9,.;:]*\-[a-zA-Z0-9,.;:]*$'
Maybe, this can help you
#!/bin/bash
while read p; do
echo $p | grep -E '\-.*\]|\].*\-' | grep "^[]a-zA-Z0-9,.;:-]*$"
done <$1
user-host:/tmp$ cat test
-i]string
]adfadfa-
string-
]string
str]ing
]123string
123string-
?????
++++++
user-host:/tmp$ ./test.sh test
-i]string
]adfadfa-
There are two questions in your post.
One is in the description:
How I can get match the two values at the same time?
That is an OR match, which could be done with a range that mix your two ranges:
pattern='^[]a-zA-Z0-9,.;:-]*$'
That will match a line that either contains one (or several) -…OR…]…OR any of the included characters. That would be all the lines (except ?????, ++++++ and as df gh) in the test script below.
Two is in the title:
… a string contains “-” and “]” at the same time
That is an AND match. The simplest (and slowest) way to do it is:
echo "$line" | grep '-' | grep ']' | grep '^[-a-zA-Z0-9,.;:]*$'
The first two calls to grep select only the lines that:
contain both (one or several) - and (one or several) ]
Test script:
#!/bin/bash
printlines(){
cat <<-\_test_lines_
asdfgh
asdfgh-
asdfgh]
as]df
as,df
as.df
as;df
as:df
as-df
as]]]df
as---df
asAS]]]DFdf
as123--456DF
as,.;:-df
as-dfg]h
as]dfg-h
a]s]d]f]g]h
a]s]d]f]g]h-
s-t-r-i-n-g]
as]df-gh
123]asdefgh
123asd-fgh-
?????
++++++
as df gh
_test_lines_
}
pattern='^[]a-zA-Z0-9,.;:-]*$'
printf '%s\n' "Testing the simple pattern of $pattern"
while read line; do
resultgrep="$( echo "$line" | grep "$pattern" )"
printf '%13s %-13s\n' "$line" "$resultgrep"
done < <(printlines)
echo "#############################################################"
echo
p1='-'; p2=']'; p3='^[]a-zA-Z0-9,.;:-]*$'
printf '%s\n' "Testing a 'grep AND' of '$p1', '$p2' and '$p3'."
while read line; do
resultgrep="$( echo "$line" | grep "$p1" | grep "$p2" | grep "$p3" )"
[[ $resultgrep ]] && printf '%13s %-13s\n' "$line" "$resultgrep"
done < <(printlines)
echo "#############################################################"
echo
printf '%s\n' "Testing an 'AWK AND' of '$p1', '$p2' and '$p3'."
while read line; do
resultawk="$( echo "$line" |
awk -v p1="$p1" -v p2="$p2" -v p3="$p3" '$0~p1 && $0~p2 && $0~p3' )"
[[ $resultawk ]] && printf '%13s %-13s\n' "$line" "$resultawk"
done < <(printlines)
echo "#############################################################"
echo
printf '%s\n' "Testing a 'bash AND' of '$p1', '$p2' and '$p3'."
while read line; do
rgrep="$( echo "$line" | grep "$p1" | grep "$p2" | grep "$p3" )"
[[ ( $line =~ $p1 ) && ( $line =~ $p2 ) && ( $line =~ $p3 ) ]]
rbash=${BASH_REMATCH[0]}
[[ $rbash ]] && printf '%13s %-13s %-13s\n' "$line" "$rgrep" "$rbash"
done < <(printlines)
echo "#############################################################"
echo
I have this
if [[ ! $newstring == *['!'##\$%^\&*()_+]* ]]
then
echo Error - Does not contain One Special Character - $newstring
i=$((i+1))
fi
Which checks if the string only has one single character from the bank, i want to check if it has more than one?
What would be the best way?
Either add a second class
if [[ "$newstring" != *['!'##\$%^\&*\(\)_+]*['!'##\$%^\&*\(\)_+]* ]]
or strip anything else out and check length
t="${newstring//[^!##\$%^\&*()_+]}"
if [ ${#t} -lt 2 ]
We can use tr to solve it.
$ string='Hello-World_12#$##*&%)(!####'
$ number=$(( $(tr -d '[[:alnum:]]' <<< "$string"|wc -m) - 1 ))
$ echo "We have $number of special characters"
$ 16
This should be short and faster.
#!/bin/bash
a='!*#%6789';
if [[ `echo $a | sed "s/\(.\)/\1\n/g"|grep -c "[[:punct:]]"` -gt 1 ]]; then echo shenzi; else echo koba; fi
grep can be useful to provide the match
grep -oP "^[^'\!'##\$%^\&*()_+]*['\!'##\$%^\&*()_+][^'\!'##\$%^\&*()_+]+$"
test
$ echo "#asdfasdf234" | grep -oP "^[^'\!'##\$%^\&*()_+]*['\!'##\$%^\&*()_+][^'\!'##\$%^\&*()_+]+$"
will match the string as
#asdfasdf234
$ echo "#asdf#asdf234" | grep -oP "^[^'\!'##\$%^\&*()_+]*['\!'##\$%^\&*()_+][^'\!'##\$%^\&*()_+]+$"
will not match the string
The if construct can be
echo $newstring| grep -oP "^[^'\!'##\$%^\&*()_+]*['\!'##\$%^\&*()_+][^'\!'##\$%^\&*()_+]+$"
if [[ $? -eq 0 ]] > /dev/null
then
echo Error - Does not contain One Special Character - $newstring
i=$((i+1))
fi
Here the regex
^[^'\!'##\$%^\&*()_+]*['\!'##\$%^\&*()_+][^'\!'##\$%^\&*()_+]+$
matches all strings with exact one occurence of the special character
I 'd like to find a bash only (no sed, awk, perl, ...) for finding out if a word is in alphabetical order, in other words every letter is.
example:
bdjkz is true,
ahjmno is true,
sdgla is false.
I'm already struggling just comparing ascii values for characters, so if anyone could point me in the right direction for that it would help a lot!
Thanks
Pure bash solution (no external tool used), using Parameter Expansion to address characters inside strings:
function compare () {
word=$1
for (( pos=0; pos<${#word}-1; pos++ )) ; do
[[ ${word:pos:1} < ${word:pos+1:1} ]] || return 1
done
return 0
}
Tested with
for word in bdjkz ahjmno sdgla ; do
if compare $word ; then
echo $word ordered
else
echo $word not ordered
fi
done
If you can utilize other command line tools (but not awk, sed, perl), you can try:
[[ "YOURSTRING" = "$(echo "YOURSTRING" | grep -o '.' | sort -n |tr -d '\n')" ]] && \
echo "Alphabetic order"
[[ ... ]] is testing the expresion
"YOURSTRING" = string comparison
"$( ... )" capture the inner workings output in a string
echo "YOURSTRING" | grep -o '.' print every character on a line from "YOURSTRING" (-o '.': print only the matches for any single character - NOTE: you might need a new version of grep for this option)
... sort -n | sort the output from 4.
... tr -d '\n' rejoin the characters from 5. (by deleting the trailing new line characters)
You can use:
p='bdjkz'
q=$(fold -w1 <<< "$p"|sort|tr -d "\n")
[[ "$p" == "$q" ]] && echo "in alphabetical order" || echo "not in alphabetical order"
s=($(echo "existingString" | grep -o .)) # put each character of input string in an array.
k=($(printf '%s\n' "${s[#]}" | sort)) # sorts the input string
if [[ "${s[*]}" == "${k[*]}" ]]; then # comparing the input string array with sorted array
echo "alphabetical"
else
echo "not alphabetical"
fi
I have a file containing on each line a string of the form
string1.string2:\string3{string4}{number}
and what I want to extract is the number. I've searched and tried for a while to get this done using sed or bash, but failed. Any help would be much appreciated.
Edit 1: The strings may contains numbers.
$ echo 'string1.string2:\string3{string4}{number}' |\
cut -d'{' -f3 | cut -d'}' -f 1
number
Using sed:
sed 's/[^}]*}{\([0-9]*\)}/\1/' input_file
Description:
[^}]*} : match anything that is not } and the following }
{\([0-9]*\)}: capture the following digits within {...}
/\1/ : substitute all with the captured number
Use grep:
grep -o '\{[0-9]\+\}' | tr -d '[{}]'
In bash:
sRE='[[:alnum:]]+'
nRE='[[:digit:]]+'
[[ $str =~ $sRE\.$sRE:\\$sRE\{$sRE\}\{($nRE)\} ]] && number=${BASH_REMATCH[1]}
You can drop the first part of the regular expression, if your text file is sufficiently uniform:
[[ $str =~ \\$sRE{$sRE}{($nRE)} ]] && number=${BASH_REMATCH[1]}
or even
[[ $str =~ {$sRE}{($nRE)} ]] && number=${BASH_REMATCH[1]}