Replace regular expression in file name

I want to use regular expressions replacement for file names in the following way.

Say I have a string '/home/directory1/sub'

I want to replace this with the string 'home/directory1/sub/' (so this needs to work for combinations of letters, numbers, characters)

or if it already had the / at the end, to leave it as is.

How would I do this in this way? I've tried using the documentation but can't seem to get it right. (Also, I can only use pre2015 commands)

[Stephen23]

@grant: just out of curiosity, what is the user case for this? Have you tried using fullfile, which avoids the need to mess around with file separators?

Answer 1

[madhan ravi]

str='/home/directory1/subs'
if strcmp(str(end),'/')
return
else
expp='$'
str=regexprep(str,expp,'/','emptymatch')
end

[Walter Roberson]

If you already tested str(end) for / then you might as well just append,

str = [str '/'];

[madhan ravi]

True sir Walter but wanted to indulge with regexprep :-)

Answer 2

[Walter Roberson]

Why are you not using fullfile() instead?

S = '/home/directory1/sub';
new_S = regexprep(S, '(?<!/)$', '/', 'emptymatch');