我有c文件,我需要在c文件的乞讨时添加一些信息。我有一个哈希表,其中键作为数字,值作为字符串。通过使用该表我正在搜索字符串找到我正在向c文件添加信息。我是通过使用我在“add information to a file using perl”问题中发布的脚本来做到这一点的。现在我需要在c文件的beginging中添加信息,如果我找到了string.In我的脚本我在字符串之前添加。 我现在应该怎么做。 提前谢谢。
答案 0 :(得分:2)
答案 1 :(得分:0)
(从我刚刚在the SitePoint forums给出的答案中交叉发布到似乎是同一个问题的答案。)
可悲的是,没有办法在文件开头插入信息而不必重写整个文件,所以你需要读入整个文件(而不是一次只读一行),确定哪个字符串(s)出现在内容中,将相应的信息项写入新文件,并(最后!)将原始内容写入新文件:
#!/usr/bin/env perl
use strict;
use warnings;
use File::Slurp;
my %strings = (
'string1' => "information \n",
'string2' => "information2 \n",
'string3' => "information3 \n",
);
my $test_string = "(" . join("|", keys %strings) . ")";
# First make a list of all matched strings (including the number of times
# each was found, although I assume that's not actually relevant)
my $code = read_file('c.c');
my %found;
while ($code =~ /$test_string/g) {
$found{$1}++;
}
# If %found is empty, we didn't find anything to insert, so no need to rewrite
# the file
exit unless %found;
# Write the prefix data to the new file followed by the original contents
open my $out, '>', 'c.c.new';
for my $string (sort keys %found) {
print $out $strings{$string};
}
print $out $code;
# Replace the old file with the new one
rename 'c.c.new', 'c.c';