I want to extract number from string. This is the string
#all/30
All I want is 30
. How can I extract? I try to use :
echo "#all/30" | sed 's/.*\/([^0-9])\..*//'
But nothing happen. How should I write for the regular expression? Sorry for bad english.
You may consider using grep to extract the numbers from a simple string like this.
echo "#all/30" | grep -o '[0-9]\+'
-o
option shows only the matching part that matches the pattern. You could try the below sed command,
$ echo "#all/30" | sed 's/[^0-9]*\([0-9]\+\)[^0-9]*/\1/'
30
[^0-9]*
[^...]
is a negated character class. It matches any character but not the one inside the negated character class. [^0-9]*
matches zero or more non-digit characters. \\([0-9]\\+\\)
Captures one or more digit characters. [^0-9]*
Matches zero or more non-digit characters. 30
echo "all/30" | sed 's/[^0-9]*\/\([0-9][0-9]*\)/\1/'
Avoid writing '.*' as it consumes entire string. Default matches are always greedy .
echo "all/30" | sed 's/[^0-9]*//g'
# OR
echo "all/30" | sed 's#.*/##'
# OR
echo "all/30" | sed 's#.*\([0-9]*\)#\1#'
without more info about possible input string we can only assume that structure is #all/
followed by the number (only)
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