fwrite

PHP: Missing records when writing to file

由 人盡茶涼 提交于 2019-12-24 05:43:55
问题 My telecom vendor is sending me a report each time a message goes out. I have written a very simple PHP script that receive values via HTTP GET. Using fwrite I write the query parameter to a CSV file.The filename is report.csv with the current date as a prefix. Here is the code : <?php error_reporting(E_ALL ^ E_NOTICE); date_default_timezone_set('America/New_York'); //setting a the CSV File $fileDate = date("m-d-Y") ; $filename = $fileDate."_Report.csv"; $directory = "./csv_archive/"; /

question with fread and fwrite in C

由 吃可爱长大的小学妹 提交于 2019-12-24 04:46:08
问题 the following is my code to write some hardcoded int values(1,2,3,4,5) into a file, close that file, open the same file in read mode and read the elements written. The fwrite happens properly as seen from the output but the fread does not read correctly. #include<stdio.h> int main() { FILE *fptr; FILE *optr; const char *filepath = "E:\\testinput.txt"; int buf[5]={1,2,3,4,5}; int obuf[5]; int value; int *ptr = &value; int num_bytes_read; int no_of_iterations; int i; int ret;//return value for

I need to read a matrix from a file which we dont know the matrix dimensions

由 瘦欲@ 提交于 2019-12-24 01:12:55
问题 I have a struct like that struct Data { int ID; double test_sample[2065][1]; int XX_row; int XX_col double **XX; //size=[2065][changing] double **alpha_new; //size=[changing][1] int alpha_new row; int alpha_new_col; double t3; double kernel_par; }person[20]; I've written this struct for every person (for 20 person) into 20 file using fwrite : fwrite(&person, sizeof( struct Data ), 1,Ptr ); Now I have 20 files in binary. Each file includes these variables for one person. All is Ok for now.

How to put new line in php file fwrite

由 纵然是瞬间 提交于 2019-12-23 06:26:17
问题 I am writing a file that is plan.php . It is a php file that I am writing. I am using \n to put the new line in that file but it is giving me save output. Here is code: $datetime = 'Monthly'; $expiry = '2017-08-07'; $expiryin = str_replace('ly', '',$datetime); if($expiryin == 'Month' || $expiryin == 'Year') { $time = '+ 1'.$expiryin.'s'; } else { $time = '+'.$expiryin.'s'; } $expiry_date = date('Y-m-d', strtotime($time, strtotime($expiry))); $string = createConfigString($expiry_date); $file =

$file->eof() always returning false when using PHP's SplFileObject in 'r' mode

由 混江龙づ霸主 提交于 2019-12-23 05:12:20
问题 Why is my PHP script hanging? $path = tempnam(sys_get_temp_dir(), '').'.txt'; $fileInfo = new \SplFileInfo($path); $fileObject = $fileInfo->openFile('a'); $fileObject->fwrite("test line\n"); $fileObject2 = $fileInfo->openFile('r'); var_dump(file_exists($path)); // bool(true) var_dump(file_get_contents($path)); // string(10) "test line // " var_dump(iterator_count($fileObject2)); // Hangs on this If I delete the last line ( iterator_count(... ) and replace it with this: $i = 0; $fileObject2-

Can fwrite & fclose be called parallely from two threads for the same file descriptor?

由 我的未来我决定 提交于 2019-12-22 07:57:43
问题 What will happen if fwrite & fclose are called in parallel from two threads for the same file descriptor? 回答1: fwrite and fclose operate on the FILE data structure. Since this is a largish data structure that does store more than just the file descriptor, the answer is bad things. Don't do this unless you ensure atomic operation using mutexes. 回答2: POSIX requires FILE access to be thread-safe, but since fclose closes the file and invalidates the pointer, there is no way (i.e. it's not just a

Write raw struct contents (bytes) to a file in C. Confused about actual size written

由 半城伤御伤魂 提交于 2019-12-21 12:42:34
问题 Basic question, but I expected this struct to occupy 13 bytes of space (1 for the char, 12 for the 3 unsigned ints). Instead, sizeof(ESPR_REL_HEADER) gives me 16 bytes. typedef struct { unsigned char version; unsigned int root_node_num; unsigned int node_size; unsigned int node_count; } ESPR_REL_HEADER; What I'm trying to do is initialize this struct with some values and write the data it contains (the raw bytes) to the start of a file, so that when I open this file I later I can reconstruct

Writing an ASCII string as binary in python

由 ◇◆丶佛笑我妖孽 提交于 2019-12-21 09:27:05
问题 I have a ASCII string = "abcdefghijk". I want to write this to a binary file in binary format using python. I tried following: str = "abcdefghijk" fp = file("test.bin", "wb") hexStr = "".join( (("\\x%s") % (x.encode("hex"))) for x in str) fp.write(hexStr) fp.close() However, when I open the test.bin I see the following in ascii format instead of binary. \x61\x62\x63\x64\x65\x66\x67 I understand it because for two slashes here ("\\x%s"). How could I resolve this issue? Thanks in advance.

Memory Mapped files and atomic writes of single blocks

由 半腔热情 提交于 2019-12-21 03:52:31
问题 If I read and write a single file using normal IO APIs, writes are guaranteed to be atomic on a per-block basis. That is, if my write only modifies a single block, the operating system guarantees that either the whole block is written, or nothing at all. How do I achieve the same effect on a memory mapped file? Memory mapped files are simply byte arrays, so if I modify the byte array, the operating system has no way of knowing when I consider a write "done", so it might (even if that is

c语言中文件的使用方法

由 送分小仙女□ 提交于 2019-12-20 08:38:40
c语言中文件的使用方法 一.文件指针的定义 FILE * fp //注意FILE的大写 二.文件的打开 fp = fopen ( "（路径）文件名.文件格式后缀" , "文件的使用方法" ） //注意路径下为//而不是/ 三.文件的使用方法 1.“r” 模式： 1.1 打开文件进行只读操作，即只能从文件读取内容。 1.2 若欲操作的文件不存在，则打开失败。 1.3 成功打开文件时，文件指针位于文件开头。 1.4 打开文件后，不会清空文件内原有内容。 1.5 可从文件中任意位置读取内容。 2."w" 模式： 2.1 打开文件进行“只写”操作，即只能向文件写入内容。 2.2 若欲操作的文件不存在，则新建文件。 2.3 成功打开文件时，文件指针位于文件开头。 2.4 打开文件后，会清空文件内原有的内容。 2.5 可向文件中任意位置写入内容，且进行写入操作时，会覆盖原有位置的内容。 3."a" 模式： 3.1 打开文件进行“追加”操作，即只能向文件写入内容。 3.2 若欲操作的文件不存在，则新建文件。 3.3 成功打开文件时，文件指针位于文件结尾。 3.4 打开文件后，不会清空文件内原有内容。 3.5 只能向文件末尾追加(写)内容。 4."r+"模式： 4.1 打开文件进行“读写”操作，即既可读取，又可写入。 4.2 若欲操作的文件不存在，则打开失败。 4.3 成功打开文件时
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