#!/bin/sh

# starting script
WatchedVar=Value
unset WatchedVar
# ending script

#!/usr/sbin/dtrace -s

#pragma D option quiet

sh$target:::line { self->line = arg1; }
sh$target:::variable-set /copyinstr(arg1) == "WatchedVar"/ {
        printf("%d: %s=%s\n", self->line, copyinstr(arg1),
	    copyinstr(arg2)); }
sh$target:::variable-unset /copyinstr(arg1) == "WatchedVar"/ {
        printf("%d: unset %s\n", self->line, copyinstr(arg1)); }

$ ./watch.d -c ./var.sh
4: WatchedVar=Value
5: unset WatchedVar

#!/usr/sbin/dtrace -s

#pragma D option quiet

sh$target:::function-entry { self->start = vtimestamp }
sh$target:::function-return {
	@[copyinstr(arg1)] = quantize(vtimestamp - self->start)
}

#!/usr/sbin/dtrace -Zs
/*
 * sh_wasted.d - measure Bourne shell elapsed times for "wasted" commands.
 *               Written for the sh DTrace provider.
 *
 * $Id: sh_wasted.d 25 2007-09-12 09:51:58Z brendan $
 *
 * USAGE: sh_wasted.d { -p PID | -c cmd }       # hit Ctrl-C to end
 *
 * This script measures "wasted" commands - those which are called externally
 * but are in fact builtins to the shell. Ever seen a script which calls
 * /usr/bin/echo needlessly? This script measures that cost.
 *
 * FIELDS:
 *              FILE            Filename of the shell or shellscript
 *              NAME            Name of call
 *              TIME            Total elapsed time for calls (us)
 *
 * IDEA: Mike Shapiro
 *
 * Filename and call names are printed if available.
 *
 * COPYRIGHT: Copyright (c) 2007 Brendan Gregg.
 *
 * CDDL HEADER START
 *
 *  The contents of this file are subject to the terms of the
 *  Common Development and Distribution License, Version 1.0 only
 *  (the "License").  You may not use this file except in compliance
 *  with the License.
 *
 *  You can obtain a copy of the license at Docs/cddl1.txt
 *  or http://www.opensolaris.org/os/licensing.
 *  See the License for the specific language governing permissions
 *  and limitations under the License.
 *
 * CDDL HEADER END
 *
 * 09-Sep-2007  Brendan Gregg   Created this.
 */

#pragma D option quiet

dtrace:::BEGIN
{
        isbuiltin["echo"] = 1;
        isbuiltin["test"] = 1;
        /* add builtins here */

        printf("Tracing... Hit Ctrl-C to end.\n");
        self->start = timestamp;
}

sh$target:::command-entry
{
        self->command = timestamp;
}

sh$target:::command-return
{
        this->elapsed = timestamp - self->command;
        this->path = copyinstr(arg1);
        this->cmd = basename(this->path);
}

sh$target:::command-return
/self->command && !isbuiltin[this->cmd]/
{
        @types_cmd[basename(copyinstr(arg0)), this->path] = sum(this->elapsed);
        self->command = 0;
}

sh$target:::command-return
/self->command/
{
        @types_wasted[basename(copyinstr(arg0)), this->path] =
            sum(this->elapsed);
        self->command = 0;
}

proc:::exit
/pid == $target/
{
        exit(0);
}

dtrace:::END
{
        this->elapsed = (timestamp - self->start) / 1000;
        printf("Script duration: %d us\n", this->elapsed);

        normalize(@types_cmd, 1000);
        printf("\nExternal command elapsed times,\n");
        printf("   %-30s %-22s %8s\n", "FILE", "NAME", "TIME(us)");
        printa("   %-30s %-22s %@8d\n", @types_cmd);

        normalize(@types_wasted, 1000);
        printf("\nWasted command elapsed times,\n");
        printf("   %-30s %-22s %8s\n", "FILE", "NAME", "TIME(us)");
        printa("   %-30s %-22s %@8d\n", @types_wasted);
}

#!/bin/sh

for i in 0 1 2 3 4 5 6 7 8 9
do      for j in 0 1 2 3 4 5 6 7 8 9
        do      /bin/echo "$i$j \c"
                /bin/date
        done
done 

$ ./sh_wasted.d -c ./bad.sh
Tracing... Hit Ctrl-C to end.
00 Wed Jan  9 10:53:02 EST 2008
01 Wed Jan  9 10:53:03 EST 2008
02 Wed Jan  9 10:53:03 EST 2008
...
98 Wed Jan  9 10:53:20 EST 2008
99 Wed Jan  9 10:53:20 EST 2008
Script duration: 17998139 us

External command elapsed times,
   FILE                           NAME                   TIME(us)
   bad.sh                         /bin/date               1067426

Wasted command elapsed times,
   FILE                           NAME                   TIME(us)
   bad.sh                         /bin/echo               1040886