Sponsored Content
Top Forums Programming strtok() gives segmentation fault!! Post 302565247 by Corona688 on Monday 17th of October 2011 11:15:46 AM
Old 10-17-2011
Quote:
Originally Posted by ashwini.engr07
Thanks Alister!
But i checked the strtok syntax shows: char * strtok ( char * str, const char * delimiters );
It's the memory that's important, not the labels. Unwritable remains unwritable memory even after you force a 'const char *' pointer into 'char *'. Which is what you are doing by putting "strings" into 'char *' variables, incidentally.

A "string" like that is a const char *, even though you're shoving it into a "char *" pointer.
Quote:
This was a sample program i was trying. In the original code, the cmd is actually passed to a function from elsewhere as const char* which i've done strdup to get char*.

So is there a way to do this by keeping cmd as char*?
You've not done strdup() here, and are trying to modify the original "string" which resides in read-only memory.

Again, 'char *' is just a label. Putting a "string" inside a "char *" does not make it modifiable.

You'll just have to make a duplicate, either with strdup() or by saving into your own local buffer.

Code:
char buf[512];
strcpy(buf, "string");

 

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. AIX

Segmentation fault

Hi , During execution a backup binary i get following error "Program error 11 (Segmentation fault), saving core file in '/usr/datatools" Riyaz (2 Replies)
Discussion started by: rshaikh
2 Replies

3. Programming

segmentation fault

Hi, I am having this segmentation fault not in the following program, bt. in my lab program . My lab program is horrible long so cannot post it here bt. I am using the following logic in my program which is giving the segmentation fault. Bt. if I run this sample program as it is it dosen't give... (3 Replies)
Discussion started by: mind@work
3 Replies

4. Programming

segmentation fault

What is segmentation fault(core dumped) (1 Reply)
Discussion started by: gokult
1 Replies

5. 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

6. 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

7. 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

8. Solaris

Segmentation fault

Hi Guys, I just installed and booted a zone called testzone. When I logged in remotely and tried changing to root user I get this error: "Segmentation fault" Can someone please help me resolve this? Thanks alot (2 Replies)
Discussion started by: cjashu
2 Replies

9. Programming

Segmentation fault

I keep getting this fault on a lot of the codes I write, I'm not exactly sure why so I'd really appreciate it if someone could explain the idea to me. For example this code #include <stdio.h> main() { unsigned long a=0; unsigned long b=0; int z; { printf("Enter two... (2 Replies)
Discussion started by: sizzler786
2 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
FBB::mlm(3bobcat)                                             OFoldStream manipulator                                            FBB::mlm(3bobcat)

NAME
FBB::mlm - Manipulator modifying left margins of OFoldStream objects SYNOPSIS
#include <bobcat/ofoldstream> or #include <bobcat/ofoldstreambuf> Linking option: -lbobcat DESCRIPTION
The mlm class implements a manipulator that can be inserted into OFoldStream objects to modify the stream's left margin by a requested amount. The request cannot result in a negative left margin value. If a negative left margin would be the arithmetic result of the request then left margin 0 will silently be used. Depending on the tab-setting of the OFoldStream the inserted value represents the number of blank space characters or the number of tab-characters that will be added to the left margin. The request will be processed at the next newline character or std::flush or std::endl manipulator that is inserted into the stream. If a line is still empty once an mlm object and a flush manipulator are inserted into the stream then the new left margin will be effective at the next word inserted into that line (cf., the example section below) A bad_cast exception is thrown when the manipulator is inserted into an ostream that is not using a OFoldStreambuf buffer. NAMESPACE
FBB All constructors, members, operators and manipulators, mentioned in this man-page, are defined in the namespace FBB. INHERITS FROM
- CONSTRUCTOR
o mlm(int addValue): The standard copy constructor is available. MEMBER FUNCTIONS
There are no public or protected member functions in this class. EXAMPLE
#include <iostream> #include <bobcat/ofoldstream> using namespace std; using namespace FBB; int main() { OFoldStream out(cout, 0, 80); out << "hello world (left margin is 0)" << mlm(4) << " " "this uses a 4 character wide left margin " << mlm(-10) << flush << "left margin -6 changed to 0, active on this line "; return 0; } FILES
bobcat/mlm - defines the class interface SEE ALSO
bobcat(7), manipulators(3bobcat), lm(3bobcat), ofoldstream(3bobcat) BUGS
None Reported. DISTRIBUTION FILES
o bobcat_3.01.00-x.dsc: detached signature; o bobcat_3.01.00-x.tar.gz: source archive; o bobcat_3.01.00-x_i386.changes: change log; o libbobcat1_3.01.00-x_*.deb: debian package holding the libraries; o libbobcat1-dev_3.01.00-x_*.deb: debian package holding the libraries, headers and manual pages; o http://sourceforge.net/projects/bobcat: public archive location; BOBCAT
Bobcat is an acronym of `Brokken's Own Base Classes And Templates'. COPYRIGHT
This is free software, distributed under the terms of the GNU General Public License (GPL). AUTHOR
Frank B. Brokken (f.b.brokken@rug.nl). libbobcat1-dev_3.01.00-x.tar.gz 2005-2012 FBB::mlm(3bobcat)
All times are GMT -4. The time now is 11:42 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy