Under /usr, list regular files whose owner-execute position has the SUID bit set.
Suppress permission-denied messages.
Which command is appropriate?
find -type f -perm -4000 finds regular files containing the SUID bit; the leading hyphen means all specified bits must be present.
Detailed explanation
find /usr -type f -perm -4000 2>/dev/nullCorrect. It searches regular files with SUID and redirects standard errors.
find /usr -type d -perm -4000 2>/dev/nullIncorrect. It limits the search to directories.
find /usr -type f -perm -2000 2>/dev/nullIncorrect. 2000 searches for SGID rather than SUID.
find /usr -type f -perm 4000 2>/dev/nullIncorrect. Exact mode matching would miss SUID files that also have ordinary permission bits.
Try it yourself
An example you can run in a temporary verification environment.
printf '%s
' '-type f=regular files' '-perm -4000=SUID bit present' '2>/dev/null=discard diagnostics'Expected result
-type f=regular files
-perm -4000=SUID bit present
2>/dev/null=discard diagnosticsKey points
- SUID is octal 4000
- -perm -MODE means contains the bits
- Limit to regular files
Notes
- Environment: GNU findutilsの構文対応表（filesystem走査なし）
- Command output formatting can vary slightly by distribution or tool version.
- Run the example in a temporary directory or process when possible.
Foundation review
Read the scope first
Check whether the command acts on the current shell, a new process, an existing process, or a file.
Verify the observable result
Use the supplied command and compare the output with the expected result.