Description
You are expected to write an “advanced” file search program for POSIX compatible operating systems. Your program must be able to search for files satisfying the given criteria, and print out the results in the form of a nicely formatted tree.
How
The search criteria can be any combination of the following (at least one of them must be employed):
- -f : filename (case insensitive), supporting the following regular expression: +
- -b : file size (in bytes)
- -t : file type (d: directory, s: socket, b: block device, c: character device f: regular file, p:
pipe, l: symbolic link)
- -p : permissions, as 9 characters (e.g. ‘rwxr-xr–’)
- -l: number of links
The symbol + means one or more of the character preceding it. You are to implement it on your own. Don’t use a library for regexp parsing. + is the only regexp operator to support, at its simplest form; no braces or brackets (i.e. { or } or [ or ]) just one or more of the preceding character. Check the output example for more details. Ask questions at the forum if it’s still unclear.
| Let’s simplify this, because I grew tired of your emails. You can have multiple occurrences of + as regexp; e.g. los+t+file that matches lossssstttttfile for instance. We’ll assume that the user will never | |
| search for strings containing the actual ASCII ‘+’ character. So there is no need for escape | |
| characters either. Just implement the + regexp, that’s all! | |
The program will additionally receive as mandatory parameter:
- -w: the path in which to search recursively (i.e. across all of its subtrees)
You can use the getopt() library method for parsing command-line arguments.
Example
./myFind -w targetDirectoryPath -f ‘lost+file‘ -b 100 -t b
means it will search in the targetDirectoryPath path, for block device files named lost+file of size exactly 100 bytes
Output In the form of nicely formatted tree
targetDirectoryPath |–subDirectory
|—-subDirectory2
|——subDirectory3
|——–LOStttttttFile
|–subDirectory6
|—-lOstFile
If no file satisfying the search criteria has been found, then simple output “No file found”. All error messages are to be printed to stderr. All system calls are to be checked for failure and the user is to be notified accordingly.
