Sponsored Content
Top Forums Programming fwrite throws segmentation fault Post 82006 by fermisoft on Friday 26th of August 2005 05:33:50 AM
Old 08-26-2005
Quote:
Originally Posted by andryk
Maybe some of those ptrs point to illegal memories ...
try writing with open/write/close only and see if sigsev occur again on writing data, if so, some ptrs may be erronous Smilie
Those pointers are valid. I attempted to call fwrite with a hardcoded string. It too crashed.
If u see the attachemnt (in my prev message), the seg. fault has occured in calloc, which is being called by fwrite. So i suspect memory leak/corruption.

You got any idea abt the impact of memory issues on fwrite function?
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Segmentation Fault

hello all, I tried a program on an array to intialise array elements from the standard input device.it is an integer array of 5 elements.but after entering the 4th element it throws a message called "Segmentation Fault" and returns to the command prompt without asking for the 5th element. ... (3 Replies)
Discussion started by: compbug
3 Replies

2. Programming

Hi! segmentation fault

I have written a program which takes a directory as command line arguments and displays all the dir and files in it. I don't know why I have a problem with the /etc directory.It displays all the directories and files untill it reaches a sub directory called peers which is in /etc/ppp/peers.the... (4 Replies)
Discussion started by: vijlak
4 Replies

3. Programming

segmentation fault

ive written my code in C for implementation of a simple lexical analyser using singly linked list hence am making use of dynamic allocation,but when run in linux it gives a segmentation fault is it cause of the malloc function that ive made use of????any suggestions as to what i could do??? thank... (8 Replies)
Discussion started by: rockgal
8 Replies

4. Programming

segmentation fault in fwrite function

Hi, my code is written in proC and it is in UNIX(AIX).I have written a small code for writing data into a binary file,but while writing my program is giving core dump. Here Is my code---- fpWriteFile = fopen(WriteFileName,"wb+"); CHAR *recvgen; recvgen = (char... (7 Replies)
Discussion started by: ajaysahoo
7 Replies

5. Programming

Segmentation fault in C

i have this code int already_there(char *client_names, char *username) { int i; for(i = 0; i<NUM; i++) { printf("HERE\n"); if (strcmp(client_names, username)==0) return(1); } return(0); } and i get a segmentation fault, whats wrong here? (7 Replies)
Discussion started by: omega666
7 Replies

6. UNIX for Advanced & Expert Users

segmentation fault with ps

What does this mean and why is this happening? $ ps -ef | grep ocular Segmentation fault (core dumped) $ ps -ef | grep ocular Segmentation fault (core dumped) $ ps aux | grep ocular Segmentation fault (core dumped) $ ps Segmentation fault (core dumped) $ pkill okular $ ps... (1 Reply)
Discussion started by: cokedude
1 Replies

7. UNIX for Dummies Questions & Answers

Segmentation fault

#include<stdio.h> #include<malloc.h> #include<unistd.h> #include<stdlib.h> void *start_1(void *argv) { printf("thread 0x%x\n",(unsigned int)pthread_self()); pthread_exit((void*)1); } void *start_2(void *argv) { printf("thread 0x%x\n",(unsigned int)pthread_self()); return (void*)2; }... (2 Replies)
Discussion started by: vincent__tse
2 Replies

8. Programming

Using gdb, ignore beginning segmentation fault until reproduce environment segmentation fault

I use a binary name (ie polo) it gets some parameter , so for debugging normally i do this : i wrote script for watchdog my app (polo) and check every second if it's not running then start it , the problem is , if my app , remain in state of segmentation fault for a while (ie 15 ... (6 Replies)
Discussion started by: pooyair
6 Replies

9. Homework & Coursework Questions

Segmentation Fault

this is a network programming code to run a rock paper scissors in a client and server. I completed it and it was working without any error. After I added the findWinner function to the server code it starts giving me segmentation fault. -the segmentation fault is fixed Current problem -Also... (3 Replies)
Discussion started by: femchi
3 Replies

10. Programming

C. To segmentation fault or not to segmentation fault, that is the question.

Oddities with gcc, 2.95.3 for the AMIGA and 4.2.1 for MY current OSX 10.14.1... I am creating a basic calculator for the AMIGA ADE *NIX emulator in C as it does not have one. Below are two very condensed snippets of which I have added the results inside the each code section. IMPORTANT!... (11 Replies)
Discussion started by: wisecracker
11 Replies
FWRITE(3)								 1								 FWRITE(3)

fwrite - Binary-safe file write

SYNOPSIS
int fwrite (resource $handle, string $string, [int $length]) DESCRIPTION
fwrite(3) writes the contents of $string to the file stream pointed to by $handle. PARAMETERS
o $handle -A file system pointer resource that is typically created using fopen(3). o $string - The string that is to be written. o $length - If the $length argument is given, writing will stop after $length bytes have been written or the end of $string is reached, whichever comes first. Note that if the $length argument is given, then the magic_quotes_runtime configuration option will be ignored and no slashes will be stripped from $string. RETURN VALUES
fwrite(3) returns the number of bytes written, or FALSE on error. NOTES
Note Writing to a network stream may end before the whole string is written. Return value of fwrite(3) may be checked: <?php function fwrite_stream($fp, $string) { for ($written = 0; $written < strlen($string); $written += $fwrite) { $fwrite = fwrite($fp, substr($string, $written)); if ($fwrite === false) { return $written; } } return $written; } ?> Note On systems which differentiate between binary and text files (i.e. Windows) the file must be opened with 'b' included in fopen(3) mode parameter. Note If $handle was fopen(3)ed in append mode, fwrite(3)s are atomic (unless the size of $string exceeds the filesystem's block size, on some platforms, and as long as the file is on a local filesystem). That is, there is no need to flock(3) a resource before calling fwrite(3); all of the data will be written without interruption. Note If writing twice to the file pointer, then the data will be appended to the end of the file content: <?php $fp = fopen('data.txt', 'w'); fwrite($fp, '1'); fwrite($fp, '23'); fclose($fp); // the content of 'data.txt' is now 123 and not 23! ?> EXAMPLES
Example #1 A simple fwrite(3) example <?php $filename = 'test.txt'; $somecontent = "Add this to the file "; // Let's make sure the file exists and is writable first. if (is_writable($filename)) { // In our example we're opening $filename in append mode. // The file pointer is at the bottom of the file hence // that's where $somecontent will go when we fwrite() it. if (!$handle = fopen($filename, 'a')) { echo "Cannot open file ($filename)"; exit; } // Write $somecontent to our opened file. if (fwrite($handle, $somecontent) === FALSE) { echo "Cannot write to file ($filename)"; exit; } echo "Success, wrote ($somecontent) to file ($filename)"; fclose($handle); } else { echo "The file $filename is not writable"; } ?> SEE ALSO
fread(3), fopen(3), fsockopen(3), popen(3), file_get_contents(3). PHP Documentation Group FWRITE(3)
All times are GMT -4. The time now is 11:13 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy