Replace first symbol of sentence with capital letter

Question

I need help with capitalizing the first letter of the first word in sentences from an input file input.txt:

this is my first sentence. and this is the second sentence. that one is the third.

I want to make the output look like this in an output file output.txt:

This is my first sentence. And this is the second sentence. That one is the third.

We can help you if you show what you've tried first. Hint: it probably involves using `perl` or `awk`. — Barmar, May 25 '13 at 18:46
Welcome to SO. Please take some time to read http://stackoverflow.com/faq — slayedbylucifer, May 25 '13 at 19:11

Ansgar Wiechers · Answer 1 · 2013-05-25T19:05:18.610

3

Try this:

sed -r "s/(^|\.\s+)./\U&/g" <input.txt >output.txt

edited May 25 '13 at 19:05

answered May 25 '13 at 18:59

Ansgar Wiechers

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Hello, I have found that it don't work with all UTF8 symbols. This is for Slovak system and sentences sometimes starting with ľ š č ť ž ý á í é ď etc. I ideas to solve this issue? – Tommy May 26 '13 at 08:53
It should work if your locale is set correctly (see [here](http://stackoverflow.com/a/67575/1630171)). – Ansgar Wiechers May 26 '13 at 08:59
Well i changed my locale to slovak utf8 and it dont work.. it replacing special characters with some robish characters. Any ideas? – Tommy May 26 '13 at 15:24
I checked with german UTF-8 locale and it worked just fine. Did you adjust `LANG` and `LC_*`? Does your terminal support UTF-8? – Ansgar Wiechers May 26 '13 at 23:17

score 1 · Accepted Answer · answered May 25 '13 at 21:28

1

bash version 4 way:

#!/usr/local/bin/bash

while IFS="." read -r -a line ; do
    for ((i=0; i<${#line[@]}; i++)) do
        if [[ $i > 0 ]]; then
            temp=$(echo ${line[$i]/ /})
            echo -n "${temp^}. "
        else
            echo -n "${line[$i]^}. "
        fi
    done
    echo
done < file

answered May 25 '13 at 21:28

jaypal singh

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Thank you it works, but it won't work with sentences starting with ľ š č ť ž ý á í é ď etc. Any ideas? – Tommy May 26 '13 at 15:27
@Tommy `bash v4` handles it. If it doesn't then your `locale` isn't set to handle this. You probably need to at least set `LC_CTYPE` to a `UTF-8` variation. – jaypal singh May 26 '13 at 16:11

fedorqui · Answer 3 · 2013-05-25T19:37:56.657

What about awk way?

$ awk -F"\. " '{OFS=". "}{for (i=0;i<=NF;i++) {sub(".", substr(toupper($i), 1,1) , $i)}} {print}' output.txt 
This is my first sentence. And this is the second sentence. That one is the third.

-F"\. " sets the field delimiter to . (dot + space).
{OFS=". "} sets the output field delimiter to . (dot + space).
'{for (i=0;i<=NF;i++) {sub(".", substr(toupper($i), 1,1) , $i)}} loops through each field capitalizing the first word of them. As first field is this is my first sentence, it just capitalizes this.

Replace first symbol of sentence with capital letter

3 Answers3