The
Time command in linux acts as Stopwatch. It provides us various forms
of information on how much time the command took to run.
The
Time command generates 3 kinds of output.
Real
: This is the amount of time between when the command was started
and completed its execution.
user : This is the time CPU took for executing the application code on behalf of the application.
user : This is the time CPU took for executing the application code on behalf of the application.
sys
: This is the time CPU took for executing the system code or
kernel code.
real
0m0.014s ([hours:] minutes : seconds)
user
0m0.000s
sys
0m0.004s
The
Time Command Displays more information besides the elapsed time .
As
basic example would be,
Dev:remoteMach:root002
$ /usr/bin/time -v tomcatstop.sh ABC-A1
Base
is /config/jboss/ews/1.0/domains/abc/ABC-A1
Home
is /software/jboss/ews32/1.0
Stopping
JBoss EWS....
Catalina
Home from SetEnv: /software/jboss/ews32/1.0
Catalina
Base from SetEnv: /config/jboss/ews/1.0/domains/abc/ABC-A1
Java
Lib Path:
/software/jboss/ews32/1.0/lib:/software/jboss/ews32/1.0/lib:
Logging
path: /logs/jboss/ews/1.0/domains/abc
Implementation Environment: dev
Using
CATALINA_BASE: /config/jboss/ews/1.0/domains/abc/ABC-A1
Using
CATALINA_HOME: /software/jboss/ews32/1.0
Using
CATALINA_TMPDIR: /config/jboss/ews/1.0/domains/abc/ABC-A1/temp
Using
JRE_HOME: /software/java32/jdk1.6.0_16
JAVA_OPTS:
-Djbs.name=ABC-A1 -server -Xms256m -Xmx256m -XX:MaxPermSize=128m
-XX:+PrintGC ***************************
Command
being timed: "tomcatstop.sh ABC-A1"
User
time (seconds): 1.52
System
time (seconds): 0.15
Percent
of CPU this job got: 108%
Elapsed
(wall clock) time (h:mm:ss or m:ss): 0:01.55
Average
shared text size (kbytes): 0
Average
unshared data size (kbytes): 0
Average
stack size (kbytes): 0
Average
total size (kbytes): 0
Maximum
resident set size (kbytes): 113328
Average
resident set size (kbytes): 0
Major
(requiring I/O) page faults: 1
Minor
(reclaiming a frame) page faults: 10294
Voluntary
context switches: 103
Involuntary
context switches: 216
Swaps:
0
File
system inputs: 0
File
system outputs: 0
Socket
messages sent: 0
Socket
messages received: 0
Signals
delivered: 0
Page
size (bytes): 4096
Exit
status: 0
The Options Include,
User time (seconds) : This is the number of seconds of CPU spent by the application.
System time (seconds) : This is the number of seconds spent in the Linux kernel on behalf of the application.
Elapsed (wall-clock) time (h:mm:ss or m:ss) : This is the amount of time elapsed (in wall-clock time) between when the application was launched and when it completed.
Percent of CPU this job got : This is the percentage of the CPU that the process consumed as it was running.
Major (requiring I/O) page faults : The number of major page faults or those that required a page of memory to be read from disk.
Minor (reclaiming a frame) page faults : The number of minor page faults or those that could be filled without going to disk.
Swaps : This is the number of times the process was swapped to disk.
Voluntary context switches : The number of times the process yielded the CPU (for example, by going to sleep).
Involuntary context switches: The number of times the CPU was taken from the process.
Page size (bytes) : The page size of the system.
Exit status : The exit status of the application
By Using the Time command we can find out how much time an application or a process from starting to completion.
