Shell Programming and Scripting

$ cat myfile
hello457903485897hello
34329048hellojsdfkljlaskdjgh182390
$ grep -c
2
$

#!/bin/ksh
cnt_words()
{
    
	file=$1
	srch="$2"
	v=$(( (`cat $file | wc -c` - `sed "s/$srch//g" $file | wc -c`) / ${#srch} ))
	echo $v
}   

cnt_words myfile hello

awk 'END{print _}{_+=NF-1}' FS="hello" input

perl -nle'++$c while /hello/g;print $c if eof' input

grep -o hello input|wc -l

cat file | sed 's/hello/|/g' |
awk 'BEGIN{FS="|"}
{
n=n+NF-1
}
END{
print n
}'

% print onehellotwoehlothree|awk -F"hello|ehlo" '$1=$1'
one two three

% print onehellotwo|awk -F"h[^o]*o" '$1=$1'
one two

vnix$ awk -F "hello" '{ sum += NF - 1 } END { print sum }' <<HERE
> hello457903485897hello
> 34329048hellojsdfkljlaskdjgh182390
> HERE
3

wc -c <$file