#!/bin/ksh
#
# USAGE ./template.sh [ -p pid ] [ -n name ] [ -s seconds ]
#
# Template to generate a big chunk of system call tracing
#

##############################
# --- Process Arguments ---
#

### default vairables
filter=0
opt_pid=0; pid=0
opt_name=0; pname=.
opt_duration=0; duration=10

### process options
while getopts p:n:s: name
do
	case $name in
	p)	opt_pid=1; pid=$OPTARG ;;
	n)	opt_name=1; pname=$OPTARG ;;
	s)	opt_duration=1; duration=$OPTARG ;;
	h|?)	cat <<-END >&2
		USAGE: ./template.sh [ -p pid ] [ -n name ] [ -s seconds ]
		
		eg,
			template.sh -p 666	# trace pid 666
			template.sh -n sshd	# trace sshd processes
			template.sh -s 100	# trace for 100 seconds
		END
		exit 1
	esac
done

### option logic
if (( opt_name || opt_pid )); then
	filter=1
fi



#################################
# --- Main Program, DTrace ---
#
/usr/sbin/dtrace -n '

/* command line arguments */
inline int OPT_pid	= '$opt_pid';
inline int OPT_name	= '$opt_name';
inline int FILTER	= '$filter';
inline int DURATION	= '$duration';
inline int PID		= '$pid';
inline string NAME	= "'$pname'";

#pragma D option quiet

/* constants */

/* setup stuff */
dtrace:::BEGIN
{
	/* reverse sorting order */
	setopt("aggsortrev");
	
	/* starting values */
	secs = DURATION;
	sys_read_count_e = 0;
	sys_write_count_e = 0;
	sys_read_count_r = 0;
	sys_write_count_r = 0;
	
	/* bzzz, krrr... */
	printf("Tracing... Please wait.\n");
	printf("[");
}

/* set filtering */
syscall::read:entry,
syscall::write:entry
{
	/* to filter or not to filter */
	this->filter = FILTER ? 0 : 1;
	
	/* open filter for these */
	(OPT_pid == 1 && PID == pid) ? this->filter = 1 : 1;
	(OPT_name == 1 && NAME == execname) ? this->filter = 1 : 1;
}

syscall::read:entry
/this->filter/
{
	/* count number of calls */
        sys_read_count_e += 1;
	
	/* record the file descriptor */
	self->fd = arg0;
	
	/* process the return */
	self->entered = 1;
}

syscall::read:return
/self->entered/
{
	/* count number of calls */
        sys_read_count_r += 1;
	@sys_read_pfd[pid, self->fd, execname] = count();
	
	self->fd = -1;
	self->entered = 0;
}

syscall::write:entry
/this->filter/
{
	/* count number of calls */
        sys_write_count_e += 1;
	
	/* record the file descriptor */
	self->fd = arg0;
	
	/* process the return */
	self->entered = 1;
}

syscall::write:return
/self->entered/
{
	/* count number of calls */
        sys_write_count_r += 1;
	@sys_write_pfd[pid, self->fd, execname] = count();
	
	self->fd = -1;
	self->entered = 0;
}

/* tralalalaaaa .. tralalalalaaaa */
profile:::tick-1sec
{
	printf(".");
	secs--;
}

/* this is the final countdown! */
profile:::tick-1sec
/secs == 0/
{
	printf("]\n");
	
	/* print totals */
	printf("\nTOTALS\n");
	printf("   %-15s  %26u\n", "READ ENTER", sys_read_count_e);
	printf("   %-15s  %26u\n", "READ RETURN", sys_read_count_r);
	printf("   %-15s  %26u\n", "WRITE ENTER", sys_write_count_e);
	printf("   %-15s  %26u\n", "WRITE RETURN", sys_write_count_r);
	printf("\n");
	
	/* print read call overview */
	printf("\nREAD CALLS RET. PER FD\n");
        printa("   %-5u %-5u %-15s %@15u\n", @sys_read_pfd);
	printf("\n");
	
	/* print write call overview */
	printf("\nWRITE CALLS RET. PER FD\n");
        printa("   %-5u %-5u %-15s %@15u\n", @sys_write_pfd);
	printf("\n");
	
	/* exiiiit */
	exit(0);
}

'