Sponsored Content
Full Discussion: Wierd C program. Help Needed
Top Forums Programming Wierd C program. Help Needed Post 302145385 by karthikb23 on Wednesday 14th of November 2007 04:28:05 AM
Old 11-14-2007
Wierd C program. Help Needed

Hi,
Please see this:
When i make a declaration as:

char *i, j[15], *k;
and then do
sprintf( k, "print.sh %s", i );

the program works fine.

But when i change the declaration to:
char *i, *k;
and then do
sprintf( k, "print.sh %s", i );
I get a segmentation fault at the 'sprintf' statement.

The program works only when j is an array of 15. Nothing less/more Smilie

Please Note: variable j is just a dummy. I do absolutely nothing with it.
Also, i know using sprintf the way i have done is illegal. The pointer is not assigned to anything, prior to such a statement.

It may be silly Smilie but could someone please explain why this happens? Guess something to do with the way memory is allocated.

Thanks in advance!
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Wierd Message????

I am getting this message when I run my script. $ runscript.sh Not connected to any service! Here is the beginning of the script: # 1 - failure # # variable declaration FILEDATE=`date +"%Y%m%d"` Not connected to any service! Right after the FILEDATE gets loaded I get that... (6 Replies)
Discussion started by: lesstjm
6 Replies

2. Programming

Wierd pipe problem

I have encountered a strange problem dealing with pipes and forking. The program basicaly does this: cat file | tbl | eqn | groff Now, I have a parent process that forks children that that exec the stuff that they should. The pipes defined in the parent are the ones used. The chain goes... (1 Reply)
Discussion started by: denoir
1 Replies

3. Solaris

wierd sparc 5

Hi! I own a sparc 5 and i seem to have a strange problem. When its off, it starts by itself... Sounds a bit strange? Iknow. Does anyone know whats causing this?? Could it be the network card? or is it someting in ENV or some other configuration?? //dOzY (5 Replies)
Discussion started by: dozy
5 Replies

4. UNIX for Dummies Questions & Answers

Wierd networking issue

I have Debian Etch release as a fresh install on a PIII to be a router/firewall. I've configured networking, and utilized Shorewall to set up iptables scripting. I've installed dhcp3, both client and server, to pull an ip from my broadband cable modem, and dish out ip's to a switch for other... (2 Replies)
Discussion started by: pflink
2 Replies

5. Programming

Help needed regarding c program

Hi, Currently, i have an application that does logging of messages into a text file and i record the timing for the messages in a format. However, i need to log the messages up to millisec level and the struct tm i am using now only support up to sec, is there any other way to get millisec? ... (2 Replies)
Discussion started by: dwgi32
2 Replies

6. UNIX for Advanced & Expert Users

Which Base Level Filesets needed by a specific program?

hello... thats a great forum btw :) my problem is that I need a list of the Base Level Filesets (BLF) which are needed by a specific program. Is there any command/tool which shows me that? during the installation I can choose "Preview only" so that I can see what BLF´s are missing etc but... (4 Replies)
Discussion started by: cypher82
4 Replies

7. UNIX for Dummies Questions & Answers

Help needed to run simple java program in linux

Hi guys , This is the first time i m running java application inside linux. i have installed jdk-6u20-linux-i586-rpm.bin jre-6u20-linux-i586-rpm.bin in my linux machine. and set JAVA_HOME and JRE_HOME variables respectively. # echo $JAVA_HOME /usr/java/jdk1.6.0_20/ # echo $JRE_HOME... (6 Replies)
Discussion started by: pinga123
6 Replies

8. Debian

Change the privileges needed to run a program

Hi everyone, I have an issue with a project of mine. I have to run a program on a terminal which requires to be logged in as su to have it run it. Given that I'm having problem to use expect to give the password I'd like to change the privilege of that program from SU to normal user ( I have the SU... (13 Replies)
Discussion started by: gaisselick87
13 Replies

9. Programming

Wrapper for unix program - urgent help needed

Hello all , i need some help asap i have a program that keeps killing the machine when i did google searches and 2 days later i ran strace it seems the programm keeps making a system call to gettimeofday to i guess increment a counter ? gettimeofday({1347986584, 464904}, NULL) = 0... (6 Replies)
Discussion started by: NetworkLearning
6 Replies

10. Homework & Coursework Questions

C++ Environment needed on Solaris,Program lifecycle

Hello, I would like to build some sample C++ application on Solaris SunOS 5.8 Generic Virtual sun4v sparc. so I would like to know what are the compilation utilities and runtime utilities I need to get in my machine and will any one explain me the detaied life cycle of program like what... (1 Reply)
Discussion started by: Revathi R
1 Replies
ASPRINTF(3)						     Linux Programmer's Manual						       ASPRINTF(3)

NAME
asprintf, vasprintf - print to allocated string SYNOPSIS
#define _GNU_SOURCE #include <stdio.h> int asprintf(char **strp, const char *fmt, ...); int vasprintf(char **strp, const char *fmt, va_list ap); DESCRIPTION
The functions asprintf and vasprintf are analogues of sprintf and vsprintf, except that they allocate a string large enough to hold the output including the terminating NUL, and return a pointer to it via the first parameter. This pointer should be passed to free(3) to release the allocated storage when it is no longer needed. RETURN VALUE
When successful, these functions return the number of bytes printed, just like sprintf(3). If memory allocation wasn't possible, or some other error occurs, these functions will return -1, and the contents of strp is undefined. NOTES
These functions are GNU extensions, not in C or POSIX. They are also available under *BSD. The FreeBSD implementation sets strp to NULL on error. SEE ALSO
free(3), malloc(3), printf(3) GNU
2001-12-18 ASPRINTF(3)
All times are GMT -4. The time now is 01:20 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy