1. Find out the files in the /tmp directory whose owner is not root and whose file name does not start with f
find /tmp -type f! -Name'f*'! -Group'root'
2. Find all files with the .conf suffix in the /etc/ directory.
find /etc/ -type f -name'*.conf'
3. Find all files in the /var directory whose owner is root and their group is mail.
find /var/ -type f -user root -group mail
4. Find the file in the /var directory 7 days ago, and the owner is not root or postfix.
find /var/ -mtime +7 -type f! -User root! -User postfix
5. Find all files in the /etc directory that are larger than 1M and are of ordinary file type
find /etc/ -type f -size +1M
6. Find files in the /etc directory that all users do not have write permission
find /etc/ -type f -perm 222
7. Find the file whose last creation time is 3 days ago and the suffix is *.log **
find / -type f -mtime +3 -name'*.log'
8. Find the file whose file name contains txt in the / directory **
find / -type f -name ' txt '
9. Find the file whose owner is oldboy and its group is oldboy
find / -type f -user oldboy -group oldboy
10. Find the file whose owner is oldboy but whose group is not oldboy
find / -type f -user oldboy! -group oldboy