The most common wildcard is the '*' which means any number of symbols. Next most common is the '?' wildcard, which denotes a single occurence of any symbol. In some instances a '.' (period or fullstop) will act as a wildcard. There are others, that work on specific occasions, to denote NOT a character, or not a digit, or not a punctuation symbol.
For example, typing *.conf will return a list of all files in a directory (and/or depending on your search settings, subdirectories).
So searching this document for wild* would return all occurencies of 'wildcard' and 'wildcards', while searching for w?l?* would also return the instances of 'will'.
Wildcards will not work in some scenarios.
- If you are an ordinary user and try to copy all files from /root to your home directory:
it will not work because bash tries to replace the * by all files in /root, but you do not have permission to list those files.
- If you use scp with wildcards, it cannot work at all:
scp user@somehost:* .