Counting letters in a file in shell script - shell

Question

I need a shell script/powershell, what count similar letters in a file.
Input:
this is the sample of this script.
This script counts similar letters.
Output:
t 9
h 4
i 8
s 10
e 4
a 2
...

Answer 1

In PowerShell, you can do it with the Group-Object cmdlet:
function Count-Letter {
param(
[String]$Path,
[Switch]$IncludeWhitespace,
[Switch]$CaseSensitive
)
# Read the file, convert to char array, and pipe to group-object
# Convert input string to lowercase if CaseSensitive is not specified
$CharacterGroups = if($CaseSensitive){
(Get-Content $Path -Raw).ToCharArray() | Group-Object -NoElement
} else {
(Get-Content $Path -Raw).ToLower().ToCharArray() | Group-Object -NoElement
}
# Remove any whitespace character group if IncludeWhitespace parameter is not bound
if(-not $IncludeWhitespace){
$CharacterGroups = $CharacterGroups |Where-Object { "$($_.Name)" -match "\S" }
}
# Return the groups, letters first and count second in a default format-table
$CharacterGroups |Select-Object #{Name="Letter";Expression={$_.Name}},Count
}
This is what the output looks like on my machine with your sample input + a linebreak

Answer 2

This one liner should do:
awk 'BEGIN{FS=""}{for(i=1;i<=NF;i++)if(tolower($i)~/[a-z]/)a[tolower($i)]++}
END{for(x in a)print x, a[x]}' file
output for your example:
u 1
h 4
i 8
l 3
m 2
n 1
a 2
o 2
c 3
p 3
r 4
e 4
f 1
s 10
t 9

Answer 3

powershell one liner:
"this is the sample of this script".ToCharArray() | group -NoElement | sort Count -Descending | where Name -NE ' '

Answer 4

echo "this is the sample of this script. \
This script counts similar letters." | \
grep -o '.' | sort | uniq -c | sort -rg
Output, sorted, most frequent letters first:
10 s
10
8 t
8 i
4 r
4 h
4 e
3 p
3 l
3 c
2 o
2 m
2 a
2 .
1 u
1 T
1 n
1 f
Notes: no sed or awk needed; a simple grep -o '.' does all the heavy lifting. To not count spaces and punctuation, replace '.' with '[[:alpha:]]' |:
echo "this is the sample of this script. \
This script counts similar letters." | \
grep -o '[[:alpha:]]' | sort | uniq -c | sort -rg
To count capital and lower case letters as one, use the --ignore-case option of sort and uniq:
echo "this is the sample of this script. \
This script counts similar letters." | \
grep -o '[[:alpha:]]' | sort -i | uniq -ic | sort -rg
Output:
10 s
9 t
8 i
4 r
4 h
4 e
3 p
3 l
3 c
2 o
2 m
2 a
1 u
1 n
1 f

Answer 5

echo "this is the sample of this script" | \
sed -e 's/ //g' -e 's/\([A-z]\)/\1|/g' | tr '|' '\n' | \
sort | grep -v "^$" | uniq -c | \
awk '{printf "%s %s\n",$2,$1}'