What permissions are needed to delete a file in unix?
I currently have a directory (udir), which has only read and write permissions for all users. This directory contains two files (file1 & file2)
I initially though that only write access was needed (on the directory) for me to be able to delete/remove a file via (rm udir/file1) but the rm command would give me access denied. when i set the permissions to read, write, and execute, the rm command works.
Obviously the execute access is needed as well but why??
I thought the execute access on a directory was to be able to make it a working a directory and search its contents and access sub directories.
Answer
You actually need read and write permissions on the directory, not on the file itself since the operation is done considering the permissions effects of directories.
A good documentation can be found on this link, which mentions the below in the section Special Considerations on Directories:
To delete a file requires both write (to modify the directory itself) and execute (to stat() the file's inode) on a directory. Note a user needs no permissions on a file nor be the file's owner to delete it!