Some Helpful Commands
| Command | Description | | --------------------------------- | ----------------------------------------------------------- | | sudo chmod -R a+rw folder/ | Give read/write perms to all users for every file in folder | | sudo reboot | Reboot | | tail -f /var/log/messages | listen to the system logs | | fuser -k 8080/tcp | kill process using port 8080 | | find . -name "foo*" 2>/dev/null | Find files recursively with match foo\ | | chown -R someuser:somegroup *.pdf | |
OS Information Commands
| Command | Description | | ----------------- | -------------------- | | cat /proc/cpuinfo | Show CPU information | | uname -a | Show OS Information |
File Hierarchy Standard (FHS)
| Path | Content | | ------ | ----------------------------------- | | /bin | Binaries (User) | | /boot | Static boot loader files | | /etc | Host specific configs | | /lib | Shared libraries and kernel modules | | /sbin | Binaries (System/root) | | /var | Varying files (e.g. Logs) | | /usr | 3rd party software | | /proc | Pseudo file system | | /sys | Pseudo file system | | /mnt | Mountpoint for internal drives | | /media | Mountpoint for external drives | | /home | User homes | | /run | PID files of running processes |
Basic Commands
File System Commands
|Command|Param|Description|
|---|---|---|
|cd|-|Navigate to last dir|
||~|Navigate to home|
||~username|Navigate to home of specified user|
|pwd||Print working dir|
|ls||Print dir content|
||-l|Format as list|
||-a|Show hidden items (-A without . and ..)|
||-r|Invert order|
||-R|Recurse|
||-S|Sort by size|
||-t|Sort by date modified|
|mkdir|-p|Create dir with parents|
|cp|-r|Copy dir|
|rmdir|-p|Remove dir and empty parents|
|rm|-rf|Remove dir recursively, -f without confirmation|
|mv||Move recursively|
|find|-iname pattern|Search dir/file case-insensitive|
||-mmin n|Last modified n minutes ago|
||-mtime n|Last modified n days ago|
||-regex pattern|Path matches pattern|
||-size n[kMG]|By file size (-n less than; +n greater than)|
||! searchparams|Invert search|
File Manipulation
|Command|Param|Description|
|---|---|---|
|cat|file|Print content|
|tac|file|Print content inverted|
|sort|file|Print sorted|
||file -r -u|Print sorted descending without dublicates|
|wc|file|Count Lines, Words, Chars (Bytes)|
|head|-n10 file|tail -n5|
|tail|-f file|Print new lines automatically|
|cut|-f -4,7-10,12,15- file|Print selected fields (tab delimited)|
||-c -4,7-10,12,15- file|Print selected characters positions|
||-f 2,4 -d, --output-delimiter=$'\t' file|Change delimiter (but use tab for output)|
|uniq|file|Hide consecutive identical lines|
||file -c|Show consecutive identical line count|
||file -u|Hide consecutive identical lines|
|file|file|Get file type
Disk and File System Management
General Disk Manipulation (non-LVM)
Creating physical partitions is not required! You can create PVs directly!
| Command | Description |
| ------------------------------------------- | ------------------------------------ |
| fdisk -l | List physical disks and partitions |
| fdisk /dev/sdb n | Create new partition |
| fdisk /dev/sdb t 8e | Change partition type to Linux LVM |
| mkfs.xfs /dev/myVG/myVol | Format LV with XFS |
| mkfs.ext4 -f /dev/myVG/myVol | Format LV with EXT4 (overwrite) |
| blkid /dev/myVG/myVol | Show UUID and formatting of volume |
| mount | Show what is mounted where |
| mount -t ext4 /dev/myVG/myVol /mountpoint | Mount LV to /mountpoint |
| umount /dev/myVG/myVol | Unmount LV from /mountpoint |
| umount /mountpoint | Unmount LV from /mountpoint |
| mount -a | Mount as configured in /etc/fstab |
| df | Show disk usage |
| xfs_growfs /dev/myVG/myVol | Resize xfs filesystem |
| resize2fs /dev/myVG/myVol | Resize ext3/4 filesystem |