bash command to count particular character in a string

kkpal · 05-27-2008, 01:46 AM

Hi all

I want to count particular character(that may be letter, numeric, or any special character)in a string. And check the consecutive repetition of any special character. How can I do it?

Thanks & Regards
KKPal

druuna · 05-27-2008, 05:03 AM

Hi,

Is this what you are looking for:

perl -lne '$HIT++ while /a/g; END { print $HIT; }'

Example run Number of o's in foobar):

Code:

$ echo "foobar" | perl -lne '$c++ while /o/g; END { print $c; }'
2

Hope this helps.

pixellany · 05-27-2008, 05:32 AM

Code:

[mherring@localhost play]$ string=aarrttiimsaapocfnaa
[mherring@localhost play]$ echo $((`echo $string|sed 's/[^a]//g'|wc -m`-1))
6

Counts the # of "a"s in the variable "string"

kkpal · 05-27-2008, 06:14 AM

Quote:

Originally Posted by pixellany

Code:

[mherring@localhost play]$ string=aarrttiimsaapocfnaa
[mherring@localhost play]$ echo $((`echo $string|sed 's/[^a]//g'|wc -m`-1))
6

Counts the # of "a"s in the variable "string"

hi

its working.

My 2nd ques. is how I know consecutive occurrence of special symbol (.-_) in a string? i.e. "test..67"

Regards
KKPal

pixellany · 05-27-2008, 06:26 AM

For multiple occurrences of any character:
a* = any number of "a"s, including zero
a+ = 1 or more "a"s

In something like SED, certain characters have special meanings--eg "." means "any character". Thus, for a literal ".", you would need "\."

\.+ = one or more literal "."s

Suggest you go to http://tldp.org and get "Bash Guide for Beginners" or the "Advanced BASH Scripting Guide"

unSpawn · 05-27-2008, 06:39 AM

Code:

string=aarrttiimsaapocfnaa; string="${string//[^a]/}"; echo ${#string}

Code:

string="a.arr.t-+ti.i.msa-apo-cfnaa"; string="${string//[a-z]/}"
for var in . - +; do str=${string//${var}/}; echo $[${#string}-${#str}]; done