如何在现有文件的midle中插入一行

Question

考虑一个例子,我想在特定模式匹配时插入几行文本(如果$ line = ~m /这里有几行/然后在下一行插入行):

*current file:*

"This is my file and i wanna insert few lines in here  and other
text of the file will continue."

*After insertion:*

"This is my file and i wanna insert few lines in here  this is my
new text which i wanted to insert and other text of the file will
continue."

这是我的代码:

my $sourcename = $ARGV[1];
my $destname = $ARGV[0];
print $sourcename,"\n";
print $destname,"\n";
my $source_excel = new Spreadsheet::ParseExcel;  
my $source_book = $source_excel->Parse($sourcename) or die "Could not open source Excel file $sourcename: $!";

my $source_cell;
#Sheet 1 - source sheet page having testnumber and worksheet number
my $source_sheet = $source_book->{Worksheet}[0];            #It is used to access worksheet

$source_cell = $source_sheet->{Cells}[1][0];                #Reads content of the cell;
my $seleniumHost = $source_cell->Value; 
print $seleniumHost,"\n";

open (F, '+>>',"$destname") or die "Couldn't open `$destname': $!";
my $line;

while ($line = <F>){
print $line;
if($line=~m/FTP/){
#next if /FTP/;
print $line;
print F $seleniumHost;}

Answer 1

perlfaq涵盖了这一点. 如何更改,删除或插入文件中的行,或附加到文件的开头？

文件是固定的数据块.它们的表现就像一张纸.你如何在一张纸的中间插入一条线？你不能,除非你留下空间.您必须重新复制整个内容,将您的行插入新副本.