Perl 向文件追加内容

当使用”>”在写模式下打开一个文件时，现有文件的内容被删除，使用打印语句添加的内容被写入文件中。在这种模式下，写入点将被设置为文件的末端。因此，文件的旧内容保持不变，使用打印语句写入文件的任何内容都被添加到文件的末尾。然而，除非文件是在表示追加和读取的+>>模式下打开的，否则不能进行读取操作。

例子

# Opening a file in read mode
# to display existing content 
open(FH, "Hello.txt") or 
     die "Sorry!! couldn't open";
  
# Reading and printing the existing
# content of the file
print"\nExisiting Content of the File:\n";
while(<FH>)
{
    print _;
}
  
# Opening file in append mode
# using >>
open(FH, ">>", "Hello.txt") or 
die "File couldn't be opened";
  
# Getting the text to be appended 
# from the user
print "\n\nEnter text to append\n";a = <>;
  
# Appending the content to file
print FH a;
  
# Printing the success message
print "\nAppending to File is Successful!!!\n";
  
# Reading the file after appending
print "\nAfter appending, Updated File is\n";
  
# Opening file in read mode to 
# display updated content
open(FH, "Hello.txt") or 
     die "Sorry!! couldn't open";
while(<FH>)
{
    print_;
}
close FH or "couldn't close";