Perl 在if语句中-e是什么意思?
我在一些Perl代码中发现了以下内容:Perl 在if语句中-e是什么意思?,perl,Perl,我在一些Perl代码中发现了以下内容: if (! -e $options{"inPath"}){ $logger->fatal("Directory \'$options{\"inPath\"}\' does not exist.\n"); } 如果语句中的-e有什么作用?请参见文档站点中的-e'/foo'返回true 如果系统中安装了perldoc,也可以从命令行访问它 perldoc -f -X 请参阅文档站点中的-e'/foo'返回true 如果系统中安装了pe
if (! -e $options{"inPath"}){
$logger->fatal("Directory \'$options{\"inPath\"}\' does not exist.\n");
}
如果语句中的-e
有什么作用?请参见文档站点中的<如果文件/foo
存在,则code>-e'/foo'
返回true
如果系统中安装了perldoc,也可以从命令行访问它
perldoc -f -X
请参阅文档站点中的<如果文件/foo
存在,则code>-e'/foo'返回true
如果系统中安装了perldoc,也可以从命令行访问它
perldoc -f -X
一元运算符-e
检查文件是否存在
Perldoc一元文件测试操作符列表:
-r File is readable by effective uid/gid.
-w File is writable by effective uid/gid.
-x File is executable by effective uid/gid.
-o File is owned by effective uid.
-R File is readable by real uid/gid.
-W File is writable by real uid/gid.
-X File is executable by real uid/gid.
-O File is owned by real uid.
-e File exists.
-z File has zero size (is empty).
-s File has nonzero size (returns size in bytes).
-f File is a plain file.
-d File is a directory.
-l File is a symbolic link (false if symlinks aren't
supported by the file system).
-p File is a named pipe (FIFO), or Filehandle is a pipe.
-S File is a socket.
-b File is a block special file.
-c File is a character special file.
-t Filehandle is opened to a tty.
-u File has setuid bit set.
-g File has setgid bit set.
-k File has sticky bit set.
-T File is an ASCII or UTF-8 text file (heuristic guess).
-B File is a "binary" file (opposite of -T).
-M Script start time minus file modification time, in days.
-A Same for access time.
-C Same for inode change time (Unix, may differ for other
platforms)
一元运算符-e
检查文件是否存在
Perldoc一元文件测试操作符列表:
-r File is readable by effective uid/gid.
-w File is writable by effective uid/gid.
-x File is executable by effective uid/gid.
-o File is owned by effective uid.
-R File is readable by real uid/gid.
-W File is writable by real uid/gid.
-X File is executable by real uid/gid.
-O File is owned by real uid.
-e File exists.
-z File has zero size (is empty).
-s File has nonzero size (returns size in bytes).
-f File is a plain file.
-d File is a directory.
-l File is a symbolic link (false if symlinks aren't
supported by the file system).
-p File is a named pipe (FIFO), or Filehandle is a pipe.
-S File is a socket.
-b File is a block special file.
-c File is a character special file.
-t Filehandle is opened to a tty.
-u File has setuid bit set.
-g File has setgid bit set.
-k File has sticky bit set.
-T File is an ASCII or UTF-8 text file (heuristic guess).
-B File is a "binary" file (opposite of -T).
-M Script start time minus file modification time, in days.
-A Same for access time.
-C Same for inode change time (Unix, may differ for other
platforms)
perldoc-f-e
。这是Perl从bash
继承的东西。请注意,记录的错误(不存在)可能不正确<代码>$代码>包含实际错误。例如,您可能没有足够的权限检查它是否存在。perldoc-f-e
。这是Perl从bash
继承的东西。请注意,记录的错误(不存在)可能不正确<代码>$代码>包含实际错误。例如,您可能没有足够的权限检查它是否存在。perldoc-f-e
也可以工作。perldoc-f-e
也可以工作。