To have data generated by your program display a page at a time, use
perl myprog.pl more
open (M, " more") die; print M "data...data...data....\n";
open(M, ">more") die; print M "data..data...data...\n";
2:
Which value of $foo is used in this statement: $r=`dir $foo` ?
The shell's value for $foo .
Perl's value of $foo is substituted, and then the dir is run.
3:
Which of the following tasks changes depending on what system you have?
Finding the amount of free disk space
Getting a directory listing
Deleting a directory
Answers
A1:
Either a or b. In the case of a, all output of myprog.pl is fed to more . In the case of b, any data written to the M file descriptor is fed to more for paging.
A2:
b. To protect $foo from Perl's expansion, you use qx`dir $foo` .
A3:
a only. Choice b can be done with glob , <*> or opendir and readdir , and c is done with rmdir .
Activities
Use the statistics functions in Hour 8, "Functions," to display even more statistics about the sizes of files in Listing 11.1.
If you have a Unix system, add your particular flavor of Unix to the freespace() function. Use the Linux example as a starting point.
