Intel XENIX 286 Programmers Guide (86) - Tenox.tc

csh: C Shell XENIX Programming
The source command is used to cause the current C shell to read commands from a file
until the end of the file. Thus
source .cshrc
can be used after editing in a change to the .cshrc file that you wish to take effect
before the next time you log in.
The time command is used to cause a command to be timed no matter how much CPU
time it takes. Thus
displays
Similarly
displays
time cp /etc/rc /usr/bi 11/rc
O.Ou 0.15 0:01 8%
time we /etc/rc /usr/bi 11/rc
52 178 1347 /etc/rc
52 178 1347 /usr/bi 1 1/rc
104 356 2694 total
0.1 u 0.15 0:00 13%
This indicates that the cp command used a negligible amount of user time (u) and about
one-tenth of a second system time (s); the elapsed time was one second (0:0 1). The word
count command we used 0.1 seconds of user time and 0.1 seconds of system time in less
than a second of elapsed time. The percentage "13%" indicates that over the period
when it was active the we command used an average of 13 percent of the available CPU
cycles of the machine.
The unalias and unset commands are used to remove aliases and variable definitions
from the C shell. The command unsetenv removes variables from the environment.
Creating Command Scripts
You can place commands in files and cause C shells to be invoked to read and execute
commands from these files, which are called C shell scripts. This section describes the
C shell features that are useful when creating C shell scripts.
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