#!/usr/bin/perl
#
# The idea with this script is, you're cd'd to /u/jasper,
# which doesn't have a db2 file in it, then invoke this
# script via aixnotes/perl_examples/check_chdir.pl
#

print "\n1: Before doing anything, your current working directory\n";
print "      according to \$ENV{\"PWD\"), is " , $ENV{"PWD"} , "\n";
print "      according to \`echo \$PWD\`, is " , `echo \$PWD`;

if (-r "db2") {print "   I see a file named db2. (??) <------------\n"}
       else {print "   I do not see a file named db2. (ok)\n"}

# # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
print "\n2: Now using Perl's chdir() function to cd to aixnotes ...\n";
chdir("aixnotes") or die "Ooops, couldn't chdir to aixnotes";

print "   And now, your current working directory\n";
print "      according to \$ENV{\"PWD\"), is " , $ENV{"PWD"} , ".  Note it's not updated.\n";
print "      according to \`echo \$PWD\`, is " , `echo \$PWD` ;

if (-r "db2") {print "   I see a file named db2. (ok)\n"}
       else {print "   I do not see a file named db2. (??) <------------\n"}

# # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
print "\n3: Now using Perl's chdir() function to cd back to /u/jasper ...\n";
chdir('/u/jasper') or die "Ooops, couldn't chdir to /u/jasper";

print "   And now, your current working directory\n";
print "      according to \$ENV{\"PWD\"), is " , $ENV{"PWD"} , "\n";
print "      according to \`echo \$PWD\`, is " , `echo \$PWD` ;

if (-r "db2") {print "   I see a file named db2. (??) <------------\n"}
       else {print "   I do not see a file named db2. (ok)\n"}

# # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
print "\n4: Now using Perl's backtick `cd` function to cd to aixnotes ...\n";
`cd aixnotes`;

print "   And now, your current working directory\n";
print "      according to \$ENV{\"PWD\"), is " , $ENV{"PWD"} , "\n";
print "      according to \`echo \$PWD\`, is " , `echo \$PWD` ;

if (-r "db2") {print "   I see a file named db2. (??) <------------\n"}
       else {print "   I do not see a file named db2.  Expected 'cause a backtick'd cd is not long lasting.\n"}

# # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
print "\n5: Now using Perl's backtick `cd` function to cd back to /u/jasper ...\n";
`cd /u/jasper`;

print "   And now, your current working directory\n";
print "      according to \$ENV{\"PWD\"), is " , $ENV{"PWD"} , "\n";
print "      according to \`echo \$PWD\`, is " , `echo \$PWD` ;

if (-r "db2") {print "   I see a file named db2. (??) <------------\n"}
       else {print "   I do not see a file named db2.  (ok)\n"}

# # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #