Process: Every program in Solaris runs as a process and there is a unique PID attached with each process. The process started/run by OS is called Daemon. It runs in background and provides services.
Each process has a PID, UID and GID associated with it. UID indicates the user who owns the process and GID denotes the group to which owner belongs to.
When a process creates another process, then the new process is called Child Process and old one is called Parent Process.
Viewing Process:
ps command: It is used to view process and is discussed below.
Syntax: ps options
Few options are discussed below:
Each process has a PID, UID and GID associated with it. UID indicates the user who owns the process and GID denotes the group to which owner belongs to.
When a process creates another process, then the new process is called Child Process and old one is called Parent Process.
Viewing Process:
ps command: It is used to view process and is discussed below.
Syntax: ps options
Few options are discussed below:
Option
|
Description
|
| -e | Prints info about every process on the system including PID, TTY(terminal identifier), TIme & CMD |
| -f | Full verbose listing which includes UIDm parent PID, process start time(STIME) |
Example:
#ps -ef | more
UID PID PPID C STIME TTY TIME CMD
root 0 0 0 Jun 02 ? 2:18 sched
root 1 0 0 Jun 02 ? 1:47 /sbin/init
root 2 0 0 Jun 02 ? 0:13 pageout
root 3 0 0 Jun 02 ? 110:25 fsflush
daemon 140 1 0 Jun 02 ? 0:15 /usr/lib/crypto/kcfd
root 7 1 0 Jun 02 ? 0:28 /lib/svc/bin/svc.startd
--More--
Now let us understand the above output column wise :
We can also search specific process using ps and grep command. For Example, if we want to search for nfsd process, we using the following command :
-sh-3.00$ ps -ef | grep nfsd
daemon 2127 1 0 Jul 06 ? 0:00 /usr/lib/nfs/nfsd
ravi 26073 23159 0 03:05:49 pts/175 0:00 grep nfsd
-sh-3.00$
pgrep command: It is used to search process by process name and displays PID of the process.
Syntax : pgrep options pattern
The options are described below:
Examples:
-sh-3.00$ pgrep j
3440
1398
-sh-3.00$ pgrep -l j
3440 java
1398 java
-sh-3.00$ pgrep -x java
3440
1398
-sh-3.00$ pgrep -n java
1398
-sh-3.00$ pgrep -U ravi
28691
28688
Using the ptree command:
It displays a process tree based on the process ID passed as an argument.
An argument of all digits are taken to be a PID, otherwise it is assumed to be a user login name.
Column
| Description |
| UID | User Name of the process owner |
| PID | Process ID |
| PPID | Parent Process ID |
| C | The CPU usage for scheduling |
| STIME | Process start time |
| TTY | The controlling terminal for process. For daemons '?' is displayed as it is started without any terminal. |
| TIME | The cumulative execution time for the process. |
| CMD | The command name, options, arguments |
We can also search specific process using ps and grep command. For Example, if we want to search for nfsd process, we using the following command :
-sh-3.00$ ps -ef | grep nfsd
daemon 2127 1 0 Jul 06 ? 0:00 /usr/lib/nfs/nfsd
ravi 26073 23159 0 03:05:49 pts/175 0:00 grep nfsd
-sh-3.00$
pgrep command: It is used to search process by process name and displays PID of the process.
Syntax : pgrep options pattern
The options are described below:
| Option |
Description
|
| -x | Displays the PID that matches exactly |
| -n | Displays only the most recently created PID that matches the pattern |
| -U uid | Displays only the PIDs that belong to the specific user. This option uses either a user name or a UID |
| -l | Displays the name of the process along with the PID |
| -t term | Displays only those processes that are associated with a terminal in the term list |
Examples:
-sh-3.00$ pgrep j
3440
1398
-sh-3.00$ pgrep -l j
3440 java
1398 java
-sh-3.00$ pgrep -x java
3440
1398
-sh-3.00$ pgrep -n java
1398
-sh-3.00$ pgrep -U ravi
28691
28688
Using the ptree command:
It displays a process tree based on the process ID passed as an argument.
An argument of all digits are taken to be a PID, otherwise it is assumed to be a user login name.
Sending a Signal to a process:
Signal is a messages that is send to a process. The process responds back by performing the action that the signal requests. It is identified by a signal number and by a signal name. There is an action associated to each signal.
Signal is a messages that is send to a process. The process responds back by performing the action that the signal requests. It is identified by a signal number and by a signal name. There is an action associated to each signal.
| Signal No. | Signal Name | Event | Definition | Default Response |
| 1 | SIGHUP | Hang Up | It drops a telephone line or terminal connection. It also causes some program to re-intialize itself without terminating | Exit |
| 2 | SIGINT | Interrupt | Its it generated from Key board. e.g. ctrl+C | Exit |
| 9 | SIGKILL | Kill | It kills the process and a process cant ignore this signal | Exit |
| 15 | SIGTERM | Terminate | It terminates the process in orderly manner. This is the default signal that kill & pkill send. | Exit |
Using kill Command: It is used to send signal to one or more processes and terminates only those process that is owned by the user. A root user can kill any process. This command sends signal 15 to the process.
Syntax: kill [-signals] PIDs
Examples:
# pgrep -l java
2441 java
#kill 2441
If the process does not terminates, issue signal 9 to forcefully terminate the process as below :
#kill -9 2441
Using pkill Command: It is used to terminate the process with signal 15. We can specify the process names(to be terminated) also in this command.
Syntax: pkill [-options] pattern
The options are same as that of pgrep command.
Example:
#pkill java
We can force the process to terminate by using signal 9:
#pkill -9 -x java
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