10-20-2008
I agree with perderabo that any use of an external program is costly in terms of system calls. So in fact we are not talking about sed (or awk) but about the usage of any program external to the shell.
I doubt that any of us can write a meaningful shellscript without any calls to external programs. I even doubt that it is possible to write such a script without any calls to external programs inside loops.
And as an example for an operation on a variable which is probably easier (and faster) to do in an external program than with shell means: perform a rot13 encryption on the contents of a string variable. In external programs this is one call (here with tr, with sed or awk its equally simple):
print - $var | tr 'abcdefghijklmnopqrstuvwxyz' 'nopqrstuvwxyzabcdefghijklm'
The same in shell variable expansion??
bakunin
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LEARN ABOUT OSF1
kernel_thread_w_arg
kernel_thread_w_arg(9r) kernel_thread_w_arg(9r)
NAME
kernel_thread_w_arg - General: Starts a kernel thread with a calling argument passed in
SYNOPSIS
thread_t kernel_thread_w_arg(
task_t task,
void (*start) (void),
void* argument );
ARGUMENTS
Specifies a pointer to a task structure. This pointer identifies the task in which the kernel_thread_w_arg routine starts the newly cre-
ated kernel thread. Specifies a pointer to a routine that is the entry point for the newly created kernel thread. Specifies the argument
that kernel_thread_w_arg passes to the entry point specified in start.
DESCRIPTION
The kernel_thread_w_arg routine creates and starts a kernel thread in the specified task at the specified entry point with a specified
argument. The kernel_thread_w_arg routine passes the specified argument to the newly created kernel thread. The kernel_thread_w_arg rou-
tine creates and starts a kernel thread with timeshare scheduling. A kernel thread created with timeshare scheduling means that its prior-
ity degrades if it consumes an inordinate amount of CPU resources. A kernel module should call kernel_thread_w_arg only for long-running
tasks. A kernel module should always attach a kernel thread to the ``first task.''
NOTES
This routine is actually a convenience wrapper for the thread_create routine (which creates the kernel thread) and the thread_start routine
(which starts the newly created kernel thread).
The kernel_thread_w_arg routine behaves identically to kernel_isrthread except that with kernel_thread_w_arg you can pass an argument to
the entry point for the newly created kernel thread.
RETURN VALUES
Upon successful completion, kernel_thread_w_arg returns a pointer to the thread structure associated with the kernel thread started at the
specified entry point. Kernel modules can use this pointer as a handle to a specific kernel thread in calls to other kernel threads-related
routines.
SEE ALSO
Routines: kernel_isrthread(9r), thread_create(9r), thread_start(9r)
Data Structures: task(9s), thread(9s)
kernel_thread_w_arg(9r)