文件和目录操作
目录
0. Handler和IO::File的比较
读写文件有两种方法: Handler和IO::File.
使用IO::File的好处是，可以把句柄当作参数，传给子例程。
use IO::File;
my $file = "io.file";
#write to the file
my $out = IO::File -> new(">$file") or die "Can't write to file $file: $!\n";
&write_file($out);
$out -> close();
#read the file
my $in = IO::File -> new("<$file") or die "Can't read file $file: $!\n";
&read_file($in);
$in -> close();
sub write_file{
my $fh = shift;
print $fh "Test data - line1\n";
print $fh "Test data - line2\n";
}
sub read_file{
my $fh = shift;
print while(<$fh>);
}
1. 读文件
1.1 使用Handler
my $filename = "file.txt";
open(FIN, "<$filename") or die "Cannot read file $filename: $!\n";
while(my $line=<FIN>){
print($line);
}
close(FIN);
1.2 使用IO::File
#read the file
my $in = IO::File -> new("<$file") or die "Can't read file $file: $!\n";
print while(<$in>);
$in -> close();
2. 写文件
2.1 使用Handler
my $filename = "file.txt";
open(FOUT, ">$filename") or die "Cannot write file $filename: $!\n";
print(FOUT, "123456\n");
close(FOUT);
2.2 使用IO::File
use IO::File;
my $file = "io.file";
#write to the file
my $out = IO::File -> new(">$file") or die "Can't write to file $file: $!\n";
print $out "Test data - line1\n";
print $out "Test data - line2\n";
$out -> close();
3. File handle重回开头或结尾
seek FH, 0, 0; # 跳到文件头
seek FH, 0, 2; # 跳到文件尾
if(eof(FH)) { # 判断是否到达文件尾
}
3. 文件查找等
3.1 File::Find(查找)
use File::Find;
find(\&wanted, "/xxx/xxx/script");
sub wanted{
$File::Find::prune = 1 if(/ex/); # prune=1, 跳过该目录
if(/\.pl$/){
print "File: $_\n"; # $_, 文件名
print "Dir : $File::Find::dir\n"; # $File::Find::dir,路径名
print "Path: $File::Find::name\n";# $File::Find::name, 全名, 即路径名/文件名.
}
}
3.2 File::Copy(复制)
use File::Copy ;
copy("file1", "file2");
move("file2","file3");
copy(\*STDIN, "file4"); #获取标准输入, 保存到file4中. 标准输入以Ctrl+D结束.
3.3 File::Basename(文件名操作)
use File::Basename;
my $full_name = "~/script/cell/scr/cell_split.pl";
my $base = basename($full_name); # cell_split.pl
my $dir = dirname($full_name); # ~/script/cell/scr
# 处理basename:
# .pl作为文件的后缀截取下来，放到第三个返回值$extension中，
# basename剩余部分放到第一个返回值$name中.
# 处理后变量内容如下:
# $name -> cell_split
# $dir -> ~/script/cell/scr/
# $extention -> .pl
my ($name, $dir, $extension) = fileparse($full_name, '\.pl');
3.x 路径操作
# 得到当前路径名, 类似于unix pwd命令.
# 如果所在的目录是link目录，则得到的link的源目录的路径.
use Cwd;
my $dir = cwd;