i need gcc manual

surya123 · 07-09-2003, 08:24 AM

i found error messages like this : Segmentation fault (Core dumped) when i compile it:"gcc LIFO.c" then run it:
"./a.out <sedikit.txt"
notes:
i use redhat 7.0
sedikit.txt is textfile, it contains:
abjad
anggur
baku
bento
laskar
tugas
tunas

i'd like to insert every text to be LIFO, but in the early i got problem like that???

listing:
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>

struct reckey
{
char *name;
struct reckey *next;
};
typedef struct reckey pkey;

int main()
{
pkey *header;
pkey *nodeBaru;
char *S;

header = (pkey *)0;

while (fgets(S,30,stdin))
{
printf("%s",S);
}
}

i need manual to learn more about gcc. Do you know where (address of http/url) can i find it?
thanks before.

TheLinuxDuck · 07-09-2003, 09:00 AM

AFA what the code is trying to do, the problem here is that you've created a pointer to a memory location (char *S), and are assigned data to it (fgets(S, 30, stdin)) before any actual heap space is assigned to the pointer (*S). In order to use the space at *S, you need to allocate it first. There are two ways to go about this:

Code:

//  staticly define S as a string, with 30 characters of space
char S[30];
  ...
  fgets(S,30,stdin);

or

Code:

 // dynamically assigned memory space for input
char *S;

S = (char *)malloc(sizeof(char) * 30);
if(S == NULL)
  perror("Unable to malloc space for S");
else {
  fgets(S,30,stdin);
  printf("%s", S);
}

One of those options should solve your segfault problem.

Oh, and anytime you post code here, please surround the code with [code] [/code] tags, so that it will look nice, and be easier to read (preserving indentations) as above.

(=

dakensta · 07-09-2003, 10:20 AM

The gcc manual is here:

http://gcc.gnu.org/onlinedocs/

but it won't teach you C

captainstorm · 07-09-2003, 11:45 AM

I like the second solution, seems to be traditional.

Qu Chen

surya123 · 07-09-2003, 06:43 PM

i have reply these, but where can i view it?
i pressed submit reply then this forum ask to re-login then i dont know where my reply gone?

test test.. (i'll click Submit Reply button)

surya123 · 07-09-2003, 06:54 PM

oh i understand now..
when i re-login, this forum can not submit my reply..

thanks @e
next i'll send it by

Code:

and

, cause i'm sure i'll have many problems in programming..

i'm trying make Last In First Out link list to text file but when i test to compile it, it occured that error message.
my basic is pascal programming, so i found myself in trouble when learn gcc.. huff

about these site http://gcc.gnu.org/onlinedocs/
yap, u r right, it wont teach me gcc, i have viewed before.

thank all, i'll try it again..