Capitalize words in a bash variable using sed

Question

I am totally new on shell scripting (actually three days only :) ) so don't shoot me .. !!

In my script I have a code that looks like that:

string="this-is-my-string"

and I like to modify the content of the variable, in order to become like that:

string="This Is My String"

I don't look for the regex that modify the original string into the modified version. I already have find the solution here.

What I am looking for, is how to modify the text inside the variable using the sed command. To be honest, I don't really know if that possible with sed. In case that modification it is not possible to be done with sed is there any other method to achieve the same result ?

You can always do `your_var=$(command with $your_var)` – fedorqui Dec 30 '14 at 10:40 — fedorqui, Dec 30 '14 at 10:40

Arjun Mathew Dan · Accepted Answer · 2014-12-30T10:45:11.107

6

string=$(sed 's/^./\u&/; s/-\(.\)/ \u\1/g' <<< $string)

Example:

sdlcb@Goofy-Gen:~/AMD$ cat File
#!/bin/bash

string="this-is-my-string"
string=$(sed 's/^./\u&/; s/-\(.\)/ \u\1/g' <<< $string)    
echo "$string"

AMD$ ./File
This Is My String

s/^./\u&/ => Capitalize the first character \u for uppercase. & => the matched pattern.

s/-$.$/ \u\1/g => substitute - followed by character to space followed by uppercase of the character. ( ) used to group pattern and \1 => first group, in this case only 1 such group is present.

edited Dec 30 '14 at 10:45

answered Dec 30 '14 at 10:38

Arjun Mathew Dan

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I get this error : ./extract.v1.sh: 50: ./extract.v1.sh: Syntax error: redirection unexpected. I think that comes from the `<<<`. What's that ? – KodeFor.Me Dec 30 '14 at 10:48
1

I changed the `#!/bin/sh` to `#!/bin/bash` and worked. Thanks ... !! – KodeFor.Me Dec 30 '14 at 10:53
I get this output on my Macbook: `uthis uis umy ustring`. – codeforester May 03 '18 at 03:03

score 4 · Answer 2 · answered Dec 30 '14 at 10:37

4

Yeah that's possible, try something like:

#!/bin/bash
string="this-is-my-string"
string=$(echo ${string} | sed 's/\-/ /g')
echo ${string}

answered Dec 30 '14 at 10:37

Jasper

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I haven't downvoted you but i think the person who did may have done so because OP also changes the first letters to capitals. Just a heads up :) – Dec 30 '14 at 10:43
Yeah didn't pay any attention to that as the OP stated he already solved that problem and said he was just after a solution to use sed for manipulating variables. – Jasper Dec 30 '14 at 10:44
Using echo has gotchas - e.g. quotes will disappear. – Ondra Žižka May 02 '18 at 23:56

gniourf_gniourf · Answer 3 · 2014-12-30T11:09:37.197

4

A pure Bash (Bash≥4) solution with parameter expansions:

$ string='this-is-my-string'
$ IFS=- read -r -a ary <<< "$string"
$ string="${ary[@]^}"
$ echo "$string"
This Is My String

edited Dec 30 '14 at 11:09

answered Dec 30 '14 at 10:43

gniourf_gniourf

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Which part capitalises the beginning of the words ? – Dec 30 '14 at 11:38
@Jidder: it's the single caret (`^`) that appears in `${ary[@]^}`: this will expand all the fields of the array `ary` with the first character converted to uppercase. – gniourf_gniourf Dec 30 '14 at 11:40
Ahh right, did not know you could do that,thanks! Are there any other transformations that can be done in a similar way ? – Dec 30 '14 at 11:41
1

@Jidder: Apart from upper/lower-casing first character or whole string, replacements, substrings (prefix/suffix), there are no other transformations. – gniourf_gniourf Dec 30 '14 at 20:38

score 3 · Answer 4 · answered Dec 30 '14 at 11:51

If you are interested this is quite simple in Python, from the interpreter:

>>> string = "this-is-my-string"
>>> string = ' '.join([ s.capitalize() for s in  string.split('-')])                                                                                                          
>>> print string
This Is My String

score 1 · Answer 5 · answered Dec 30 '14 at 11:06

You can try it like this too

 echo '"this-is-my-string"'|sed 's/-/ /g;s/\([^"]\)\(\S*\s*\)/\u\1\2/g'

or

echo "$string"|sed 's/-/ /g;s/\([^"]\)\(\S*\s*\)/\u\1\2/g'

the \S is a metacharacter that matches any character that is not a space/whitespace and \s matches any characters that is a space

Jotne · Answer 6 · 2014-12-30T11:58:41.133

Here is an awk solution:

echo "this-is-my-string" | awk -F- '{for (i=1;i<=NF;++i) $i=toupper(substr($i,1,1)) substr($i,2)}1'
This Is My String

string='this-is-my-string'
string=$(awk -F- '{for (i=1;i<=NF;++i) $i=toupper(substr($i,1,1)) substr($i,2)}1' <<< "$string")
echo "$string"
This Is My String

Here is another awk

echo "this-is-my-string" | awk -F- '{for(i=1;i<=NF;i++)sub(/./,toupper(substr($i,1,1)),$i)}1'
This Is My String

Capitalize words in a bash variable using sed

6 Answers6