My RHEL Notes: Difference between revisions
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running process is flagged to be scheduled in CPU cycles | running process is flagged to be scheduled in CPU cycles | ||
# ps -ax | <pre># ps -ax | ||
Command column square brackets [ ] mean kernel started process. | Command column square brackets [ ] mean kernel started process. | ||
| Line 30: | Line 30: | ||
# jobs // to get job # | # jobs // to get job # | ||
kill -KILL %[job #] // to kill by job # | kill -KILL %[job #] // to kill by job # | ||
</pre> | |||
== disk usage == | == disk usage == | ||
use du command | <pre>use du command | ||
# du -sh /* 2> /dev/null // use STD ERROR to bit bucket | # du -sh /* 2> /dev/null // use STD ERROR to bit bucket | ||
# ps -eo "%c %n %y" // see ps man page, like %P & %U | # ps -eo "%c %n %y" // see ps man page, like %P & %U | ||
</pre> | |||
== Software Management == | == Software Management == | ||
| Line 59: | Line 61: | ||
== man pages == | == man pages == | ||
$ man -k record | grep -i dvd | <pre>$ man -k record | grep -i dvd | ||
# man -k pdf</pre> | |||
# man -k pdf | |||
== network stuff == | == network stuff == | ||
$ mtr [destination] | |||
== users & groups == | == users & groups == | ||
# egrep 'dave|darth|luke' /etc/{passwd,group,shadow} | <pre># egrep 'dave|darth|luke' /etc/{passwd,group,shadow}</pre> | ||
== permissions == | |||
umask blocks out bits | |||
=== special permissions === | |||
<insert graphics example> | |||
<pre>[student@desktop12 test]$ pwd | |||
/home/student/test | |||
[student@desktop12 test]$ touch file1 | |||
[student@desktop12 test]$ touch file2 | |||
[student@desktop12 test]$ touch file3 | |||
[student@desktop12 test]$ touch file4 | |||
[student@desktop12 test]$ touch file5 | |||
[student@desktop12 test]$ touch file6 | |||
[student@desktop12 test]$ touch file7 | |||
[student@desktop12 test]$ chmod 1777 file1 | |||
[student@desktop12 test]$ chmod 2777 file2 | |||
[student@desktop12 test]$ chmod 3777 file3 | |||
[student@desktop12 test]$ chmod 4777 file4 | |||
[student@desktop12 test]$ chmod 5777 file5 | |||
[student@desktop12 test]$ chmod 6777 file6 | |||
[student@desktop12 test]$ chmod 7777 file7 | |||
[student@desktop12 test]$ ls -l | |||
total 0 | |||
-rwxrwxrwt. 1 student student 0 Sep 29 10:19 file1 | |||
-rwxrwsrwx. 1 student student 0 Sep 29 10:19 file2 | |||
-rwxrwsrwt. 1 student student 0 Sep 29 10:19 file3 | |||
-rwsrwxrwx. 1 student student 0 Sep 29 10:19 file4 | |||
-rwsrwxrwt. 1 student student 0 Sep 29 10:19 file5 | |||
-rwsrwsrwx. 1 student student 0 Sep 29 10:19 file6 | |||
-rwsrwsrwt. 1 student student 0 Sep 29 10:20 file7 | |||
[student@desktop12 test]$</pre> | |||
== | == admin remote system == | ||
$ ssh -X hostname | |||
$ gedit filename | |||
ssh-copy-id | |||
$ cd ~; tar -zcvf newtarball.tgz . | |||
== general services == | |||
/etc/services | |||
/etc/init.d | |||
/etc/inittab | |||
chkconfig | |||
service | |||
netstat | |||
== pending categorization == | |||
<pre># ldd /usr/bin/sshd</pre> | |||
<center>[[Linux | To Linux]]</center> | <center>[[Linux | To Linux]]</center> | ||
Latest revision as of 15:33, 29 September 2011
general notes[edit | edit source]
$ cmd [-opt] [arguments]
cmd uses $PATH and arguments uses $PWD. Arguments are local to current working directory
Press TAB TAB to list available commands in $PATH or list available arguments in $PWD.
managing system resources[edit | edit source]
Ctrl+Z jobs fg %[job #] ps [-fax]
Process Status can be suspended (S+PROCESS STATE CODES in $ ps man page to view), stopped (T), running (R+), zombie
running process is flagged to be scheduled in CPU cycles
# ps -ax Command column square brackets [ ] mean kernel started process. kill -l // list kill options process priority # nice cmd # renice cmd # jobs // to get job # kill -KILL %[job #] // to kill by job #
disk usage[edit | edit source]
use du command # du -sh /* 2> /dev/null // use STD ERROR to bit bucket # ps -eo "%c %n %y" // see ps man page, like %P & %U
Software Management[edit | edit source]
# rpm -qf # rpm -ql # rpm -V # rpm -vi # rpm -qa yum resolves dependencies rpm installs & deletes # ls /etc/yum.repos.d/
man pages[edit | edit source]
$ man -k record | grep -i dvd # man -k pdf
network stuff[edit | edit source]
$ mtr [destination]
users & groups[edit | edit source]
# egrep 'dave|darth|luke' /etc/{passwd,group,shadow}
permissions[edit | edit source]
umask blocks out bits
special permissions[edit | edit source]
<insert graphics example>
[student@desktop12 test]$ pwd /home/student/test [student@desktop12 test]$ touch file1 [student@desktop12 test]$ touch file2 [student@desktop12 test]$ touch file3 [student@desktop12 test]$ touch file4 [student@desktop12 test]$ touch file5 [student@desktop12 test]$ touch file6 [student@desktop12 test]$ touch file7 [student@desktop12 test]$ chmod 1777 file1 [student@desktop12 test]$ chmod 2777 file2 [student@desktop12 test]$ chmod 3777 file3 [student@desktop12 test]$ chmod 4777 file4 [student@desktop12 test]$ chmod 5777 file5 [student@desktop12 test]$ chmod 6777 file6 [student@desktop12 test]$ chmod 7777 file7 [student@desktop12 test]$ ls -l total 0 -rwxrwxrwt. 1 student student 0 Sep 29 10:19 file1 -rwxrwsrwx. 1 student student 0 Sep 29 10:19 file2 -rwxrwsrwt. 1 student student 0 Sep 29 10:19 file3 -rwsrwxrwx. 1 student student 0 Sep 29 10:19 file4 -rwsrwxrwt. 1 student student 0 Sep 29 10:19 file5 -rwsrwsrwx. 1 student student 0 Sep 29 10:19 file6 -rwsrwsrwt. 1 student student 0 Sep 29 10:20 file7 [student@desktop12 test]$
admin remote system[edit | edit source]
$ ssh -X hostname
$ gedit filename
ssh-copy-id
$ cd ~; tar -zcvf newtarball.tgz .
general services[edit | edit source]
/etc/services
/etc/init.d
/etc/inittab
chkconfig
service
netstat
pending categorization[edit | edit source]
# ldd /usr/bin/sshd