ЭЛЕКТРОННАЯ БИБЛИОТЕКА КОАПП |
Сборники Художественной, Технической, Справочной, Английской, Нормативной, Исторической, и др. литературы. |
12. Directory AccessContents: 12.1 Moving Around the Directory TreeBy now, you're probably familiar with the notion of the current directory and using the shell's cd command. In systems programming, you'd be invoking the chdir system call to change the current directory of a process, and this is the name used by Perl as well. The chdir("/etc") || die "cannot cd to /etc ($!)"; The parentheses are optional, so you can also get away with stuff like this: print "where do you want to go? "; chomp($where = <STDIN>); if (chdir $where) { # we got there } else { # we didn't get there } You can't find out where you are without launching a pwd command.[1] We'll learn about launching commands in Chapter 14, Process Management.
Every process[2] has its own current directory. When a new process is launched, it inherits its parent's current directory, but that's the end of the connection. If your Perl program changes its directory, it won't affect the parent shell (or whatever) that launched the Perl process. Likewise, the processes that the Perl program creates cannot affect that Perl program's current directory. The current directories for these new processes are inherited from the Perl program's current directory.
The |