#!/bin/perl
open( $WP, ">/home/Octa.txt" );
# Subroutine test
sub test {
$var1 = shift;
print $WP "TESTING\n";
}
# Subroutine func
sub func {
$var = shift;
if ( $var eq "Ocat" ) {
print $WP "String found\n";
test($var);
}
else {
print $WP "String not found\n";
}
}
$var3 = "Octa";
func($var3);
问题是代码无法在test子例程或{＆lt; func if else`部分的subroutine, but it prints in the条件内写入任何内容＃39; FUNC＆＃39;子程序。
答案 0 :(得分：3)
首先，有一个拼写错误 - 您针对$var测试"Ocat"，而Octa则打算测试test。
因此永远不会调用String not found子例程，只打印use warnings;
use strict;
my $file = 'Octa.txt';
open my $WP, '>', $file or die "Can't open $file: $!";
my $var3 = "Octa";
func($WP, $var3);
#Subroutine test
sub test{
my ($fh, $var1) = @_;
print $fh "TESTING\n";
}
#Subroutine func
sub func{
my ($fh, $var) = @_;
if ($var eq "Octa"){
print $fh "String found\n";
test($fh, $var);
}
else {
print $fh "String not found\n";
}
}
。
如果更正并且输出文件位于用户可写位置，则您的程序可以正常工作。
但是，有必要进行一些改进。
/home我已更改输出文件名，因为用户通常无法写入open目录。
评论
使用open的三参数形式要好得多，在这种情况下，你会得到一个词法文件句柄，它可以很好地传递并且是作用域的。至少可以说，这个问题是一个很好的例子，说明全局文件句柄如何让事情变得混乱。
始终检查/home来电。首先，你真的可以写到use warnings;目录吗？
请始终使用use strict;和/home
还有另一种失败的可能性，它将上述评论中的做法结合在一起。
open中的文件通常不可由用户写入，在这种情况下，发布的程序无法正常工作。
但是如果没有检查use warnings（会失败）并且没有$WH（每当我们触摸无效的import requests
import io
import mimetypes
import xml.etree.ElementTree as ET
import sys
api = ''
urls =["https://.../api/images/products/22",
"https://.../api/images/products/31",
"https://.../api/images/products/37",
"https://.../api/images/products/46",
"https://.../api/images/products/212"]
def encode_multipart_formdata(file_name,content):
"""Encode files to an http multipart/form-data.
:param files: a sequence of (type, filename, value)
elements for data to be uploaded as files.
:return: headers and body.
"""
BOUNDARY = '----------ThIs_Is_tHe_bouNdaRY_$'
CRLF = '\r\n'
L = []
L.append('--' + BOUNDARY)
L.append(
'Content-Disposition: form-data; \
name="%s"; filename="%s"' % ("image", file_name))
L.append('Content-Type: %s' % get_content_type(file_name))
L.append('')
L.append(content)
L.append('--' + BOUNDARY + '--')
L.append('')
body = CRLF.join(L)
headers = {
'Content-Type': 'multipart/form-data; boundary=%s' % BOUNDARY
}
return headers, body
def get_content_type(file_name):
"""Retrieve filename mimetype.
:param filename: file name.
:return: mimetype.
"""
return mimetypes.guess_type(file_name)[0] or 'application/octet-stream'
def get_image_url(url):
"""get from a given url the image url"""
r = requests.get(url, auth=(api,""))
tree = ET.fromstring(r.content)
return tree.find("image").find("declination").get("{http://www.w3.org/1999/xlink}href")
def delete_image(url):
"""deletes the image on prestashop given by url"""
url2 = get_image_url(url)
requests.delete(url2, auth=(api,""))
def load_image(file_name):
"""loads image to upload"""
fd = io.open(file_name, "rb")
content = fd.read()
fd.close()
return content, file_name
def upload_image(url, file_name):
"""uploads new image to a given url"""
content, file_name = load_image(file_name)
header, body = encode_multipart_formdata(file_name, content)
requests.post(url, data=body, auth=(api,""), headers=header)
if __name__ == "__main__":
file_name = sys.argv[1]
content, file_name = load_image(file_name)
for i in urls:
delete_image(i)
upload_image(i,file_name)
文件句柄时都会打印），我们将看不到任何这些错误;相反，程序将安静地运行并完成，但它不会写输出文件。