Linux Notes from Keith
From DreamsteepWiki
(One Year's Worth of) Linux Notes From Keith
General Linux Commands (Not Executable Code)
su - switch user df - disk usage top - list or running proceses and process id (PID) kill 0 (PID),kill -2(PID) kill a process umount - unmount a device free - list free memory tee - write a file from a pipe usermod umask chgrp chown chmod du
Permissions (Not Code)
Octal 0 | --- 1 | --x 2 | -w- 3 | -wx 4 | r-- 5 | r-x 6 | rw- 7 | rwx 4- read 2-write 1-exe ------------------------ | 876 | 543 | 210 | | rwx | rwx | rwx | | user |group | other | ------------------------ 1-d (dir) 2,3,4 (owner) 5,6,7 (group) 8,9,10 (user) S-set user ID /set group ID either inherit user's permissions or the directory's permissions
Umask
type umask to see your octal umask value
inherited from login may be found in .cshrc .login (/user)
I Set This In:
/etc/bashrc >> add a line or modify >>
umask 022
(or whatever )
Install Nvidia On Fedora
GETTING MAYA TO RUN ON FC7
things to try: copy libGLU.so from install DVD
Nvidia Quadro FX Family To set hardware overlay planes on NVIDIA quadro cards you will need to enable "CIOverlay" in the XF86Config file. ex.
Section "Device" Option "CIOverlay" "on"
run nvidia-settings first (seems to fix some gl bug)
other things to try :
play with libXP.so libraries and links (bad idea but seems to work)
Run the following three commands in yum, pray it works without error (about 95% chance it will):
Install Needed Libraries
yum install kernel-devel xorg-x11-server-sdk pkgconfig yum update reboot
download appropriate .run package from nvidia
kill xserver
init 3
login and run your .run file
restart xserver or reboot
init 5
You should see an Nvida logo if it worked.
Alternate Method
setup livna repository config
run the following to install the livna (seems to work when nvidia wont but the quality is often poor, I had rendering problems with these drivers)
init 3 yum install kmod-nvidia nvidia-config-display enable init 5
Test If You Have OpenGL Working
glxinfo , glxgears
Get The Current Running Kernel Version
uname -r
Identify if your os is 64 bit
uname -a
Adjust Monitor Settings
sytem-config-display
xorg (xserver) log path for debugging
var/log/xorg log
(Notes are hard to read, I don't remember this )
Setting Up/Notes On Grub
To Boot Into Winodows XP From Command Line
rootnoverify (hd0,0) (USUALLY DRIVE 1,partition 1) makeactive chainloader +1 boot
FSTAB _FILE SYSTEM TABLE
a file that will auto mounf drives and devices for you upon bootup
dont change ANYTHING , just copy the last line and change it , it should look like this
device |mountpoint |type of mount |options |options
/dev/sdc2 /mnt/sdc2 auto defaults 0 0
this is of course an example using drive sdc2 , etc additoinal lines can be added for each partition, device
Hard Drives
To See Available Space
df df -h
To See All Devices
fdisk -l
Sometimes a user may need more permisions to run, on some systems fdisk can only be:
/sbin/fdisk -l
To Format A Drive
sfdisk /dev/sdb (drive) -uM (units Megabyte for readability) << EOF (pause and add aditional lines
sfdisk /dev/sdb -uM <<EOF 100,000 ; ; EOF
After Partitioning, You Have To Format (It Is Very Fast <2 Min.)
mkfs.ext3 device
(or ext2 for older systems)
Networking
set hostname though system settings GUI panel in GNOME
hostname
is your name and domain it will be localhost.localdomain by default
Network Setup
etc/hosts
This is a table of name to IP address links (this needs to be setup to run my render farm, so each machine is identified).
Network Admin Stuff
Setting Up Encryption With SSH
RSA/DSA Key Encryption
set up etc/hosts file for server machine
ssh-keygen
(enter for default path /home/user/.ssh/id.rsa OR /root/.ssh/id.rsa)
copy id_rsa to host machine , same path (/home/user/ ) but name it known_hosts instead append it to the file if it exists already to add a new public key
SCP (moving folders and files)
ssh 192.168.0.9 ssh filename user@192.168.0.9
SCP
scp keith@192.168.0.9:/pathtosave
For folders use the recursive flag
scp -r keith@192.168.0.9:/pathtosave
Running a Debugger (for Maya command )
maya -d gdb
Delete A Partition
run command, a series of options will follow
fdisk /dev/sdb p...(partition) d... (delete) #... number w...finish reboot
Manual Grub Instalation
(These Notes Are Shady At Best. I Still Don't Know How To Do This, but I Have Gotten it to Work)
- Insert FC install disk
- Type linux rescue
To get into system type:
chroot /mnt/sysimage
chroot /mnt/sysimage grub root(hd0,0) ext2fs,partition type 0x83
more GRUB notes
linux rescue chroot /mnt/sysimage grub_install /dev/hda (or /sda)
Finding The Fedora Trashcan Files
/home/user/.Trash (the dot means it is hidden,like .SSH folder)
For removeable media it is in
/media/disk/.Trash-Keith (username)
Setting Environment Variables
There is a folder:
/etc/profile.d/
All shell scripts in this folder are sourced at login.
Simply add a shell that uses the export command to get an environment variable
export myvar=3.1459 export myothervar=kilroywashere
Will create 2 variables.
It is usually better to put multiple files with less variables for organization.
TO ADD TO YOUR PATH VARIABLE
PATH=$PATH\:/dir/path ; export PATH
Cron Jobs
Use the crontab command.
Each user gets a crontab, I use root as the user for system cronjobs.
crontab -e
This will launch vi , the text editor.
VI
two modes , insert , edit
Cycle through them with the Insert key.
hit escape to exit 2 modes
Hit Shift z (twice?) to exit.
YUM
disk_usage
du --max-depth=1 du -k --max-depth=1 /home | sort -nr
rename a file
mv file file2
RPM
rpm -Uvh filetoinstall.rpm
extract a tarball
tar -xf file.tar.gz
