Removing Files

Sometime you may encounter problems in removing (rm) files in a UNIX environment. It could be due to the file name consists of non-printable characters (such as space, Ctrl-C, ...) or the file name starts with a minus ("-")

Lets tackle the easy one, that is file name with a "-". If you "rm" directory on the file, the "rm" command will complaint illegal option. What you can do is either provide a relative path "./" or full path to avoid having the first character to be the minus sign.

$ touch ./-abc
$ rm -abc
rm: illegal option -- a
rm: illegal option -- b
rm: illegal option -- c
usage: rm [-fiRr] file ...
$ rm ./-abc

So far so good. How about files with non-printable characters. Let's create some of these files. To introduce control character, type in Ctrl-V followed by whatever control character.

$ touch "abc def"
$ touch "hij^Clkm"
$ touch "rst^Mxyz"
$ ls
xyz def  hijlkm  rst

If you really want to see the actual character set of these file names, you can do an "octal dump" on the output of "ls -1" (ls minus one). i.e., one file name per line.

$ ls -1 | od -c
0000000   a   b   c       d   e   f  \n   h   i   j 003   l   k   m  \n
0000020   r   s   t  \r   x   y   z  \n
0000030

If you have problem deleting any of the file, what you can do is to find out the i-node number of that file and delete it using find

$ ls -li
total 0
    297552 -rw-------   1 chihung  gdz            0 Oct 15 20:18 abc def
    297551 -rw-------   1 chihung  gdz            0 Oct 15 20:18 hijlkm
xyz 297550 -rw-------   1 chihung  gdz            0 Oct 15 20:18 rst

$ find . -inum 297550 -exec rm -i {} \;
xyz (yes/no)? yes

$ ls -li
total 0
    297552 -rw-------   1 chihung  gdz            0 Oct 15 20:18 abc def
    297551 -rw-------   1 chihung  gdz            0 Oct 15 20:18 hijlkm

Remember to use "rm -i" in "find", just in case.