mkstemp

Python write in mkstemp() file

由 ≡放荡痞女 提交于 2020-03-18 05:02:44
问题 I am creating a tmp file by using : from tempfile import mkstemp I am trying to write in this file : tmp_file = mkstemp() file = open(tmp_file, 'w') file.write('TEST\n') Indeed I close the file and do it proper but when I try to cat the tmp file, it stills empty..It looks basic but I don't know why it doesn't work, any explanations ? 回答1: mkstemp() returns a tuple with a file descriptor and a path. I think the issue is that you're writing to the wrong path. (You're writing to a path like '(5,

Python write in mkstemp() file

由 好久不见. 提交于 2020-03-18 05:02:19
问题 I am creating a tmp file by using : from tempfile import mkstemp I am trying to write in this file : tmp_file = mkstemp() file = open(tmp_file, 'w') file.write('TEST\n') Indeed I close the file and do it proper but when I try to cat the tmp file, it stills empty..It looks basic but I don't know why it doesn't work, any explanations ? 回答1: mkstemp() returns a tuple with a file descriptor and a path. I think the issue is that you're writing to the wrong path. (You're writing to a path like '(5,

Is there a way to automatically close a Python temporary file returned by mkstemp()

由 ╄→гoц情女王★ 提交于 2019-12-12 19:08:41
问题 Normally I process files in Python using a with statement, as in this chunk for downloading a resource via HTTP: with (open(filename), "wb"): for chunk in request.iter_content(chunk_size=1024): if chunk: file.write(chunk) file.flush() But this assumes I know the filename. Suppose I want to use tempfile.mkstemp() . This function returns a handle to an open file and a pathname, so using open in a with statement would be wrong. I've searched around a bit and found lots of warnings about being

Python - How do I convert “an OS-level handle to an open file” to a file object?

由 风格不统一 提交于 2019-12-03 06:13:35
问题 tempfile.mkstemp() returns: a tuple containing an OS-level handle to an open file (as would be returned by os.open()) and the absolute pathname of that file, in that order. How do I convert that OS-level handle to a file object? The documentation for os.open() states: To wrap a file descriptor in a "file object", use fdopen(). So I tried: >>> import tempfile >>> tup = tempfile.mkstemp() >>> import os >>> f = os.fdopen(tup[0]) >>> f.write('foo\n') Traceback (most recent call last): File "

How to create a std::ofstream to a temp file?

由 烂漫一生 提交于 2019-11-30 11:18:22
问题 Okay, mkstemp is the preferred way to create a temp file in POSIX. But it opens the file and returns an int , which is a file descriptor. From that I can only create a FILE*, but not an std::ofstream , which I would prefer in C++. (Apparently, on AIX and some other systems, you can create an std::ofstream from a file descriptor, but my compiler complains when I try that.) I know I could get a temp file name with tmpnam and then open my own ofstream with it, but that's apparently unsafe due to

How to create a std::ofstream to a temp file?

由 瘦欲@ 提交于 2019-11-29 23:37:36
Okay, mkstemp is the preferred way to create a temp file in POSIX. But it opens the file and returns an int , which is a file descriptor. From that I can only create a FILE*, but not an std::ofstream , which I would prefer in C++. (Apparently, on AIX and some other systems, you can create an std::ofstream from a file descriptor, but my compiler complains when I try that.) I know I could get a temp file name with tmpnam and then open my own ofstream with it, but that's apparently unsafe due to race conditions, and results in a compiler warning (g++ v3.4. on Linux): warning: the use of `tmpnam'

mkstemp() implementation for win32

由 孤街浪徒 提交于 2019-11-29 14:03:03
问题 Can anybody point me to the code that implements mkstemp() (C/C++) on Win32, or very close analog. Must be race-free. It's supposed to look like #include <windows.h> #include <io.h> // port of mkstemp() to win32. race-free. // behaviour as described in http://linux.die.net/man/3/mkstemp // int mkstemp(char *template) { ... } Thanks 回答1: You can use the following function which is extracted from wcecompat library (from file src/stdlib_extras.cpp ) /* mkstemp extracted from libc/sysdeps/posix

How to get a FILE pointer from a file descriptor?

由 蓝咒 提交于 2019-11-28 15:56:48
I'm playing around with mkstemp() , which provides a file descriptor, but I want to generate formatted output via fprintf() . Is there an easy way to transform the file descriptor provided by mkstemp() into a FILE * structure that is suitable for use with fprintf() ? Richard Pennington Use fdopen() : FILE* fp = fdopen(fd, "w"); FILE* f = fdopen(d, "w"); man fdopen output: SYNOPSIS #include <stdio.h> FILE * fdopen(int fildes, const char *mode); The fdopen() function associates a stream with the existing file descriptor, fildes . The mode of the stream must be compatible with the mode of the

How to get a FILE pointer from a file descriptor?

由 ε祈祈猫儿з 提交于 2019-11-27 09:27:31
问题 I'm playing around with mkstemp() , which provides a file descriptor, but I want to generate formatted output via fprintf() . Is there an easy way to transform the file descriptor provided by mkstemp() into a FILE * structure that is suitable for use with fprintf() ? 回答1: Use fdopen(): FILE* fp = fdopen(fd, "w"); 回答2: FILE* f = fdopen(d, "w"); man fdopen output: SYNOPSIS #include <stdio.h> FILE * fdopen(int fildes, const char *mode); The fdopen() function associates a stream with the existing
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