Useful Commands
Parse out non-commented lines from a file:
grep ‘^[^#]‘ filename
How to test an Internet connection through a browser:
telnet google.com 80
Trying 64.233.167.99…
Connected to google.com (64.233.167.99).
Escape character is ‘^]’.
GET / HTTP/1.0
HTTP/1.0 200 OK
Check backporting:
rpm –changelog -ql packagename | grep CAN-xxxxx
Verify RPMs:
rpm -Va
Options:
- S file Size differs
- M Mode differs (includes permissions and file type)
- 5 MD5 sum differs
- D Device major/minor number mismatch
- L readLink(2) path mismatch
- U User ownership differs
- G Group ownership differs
- T mTime differs
Check the changelog on a rpm package:
rpm -q –changelog packagename
How to generate a SSH client key:
ssh-keygen -t rsa
How to sync the hardware clock with the current system time without rebooting:
hwclock –systohc
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To get non-commented lines out of a file, you can also use:
grep -v “^#” filename
Posted March 27, 2007, 3:09 pm