c file handling on linux
 

running the programm that is reading a file
after running its exe gives the error segmentation fault

It's difficult to say something with so few infos...

Well, can you give us more details (source, what compiler, the command you used for compiling and after to run the program) ?

code is #include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<time.h>
#include<unistd.h>
int main ()
{
char *rept_cell[900];
char cell_alarm[5800];
char temp_cell_all[5800];
char cell_alarm1[2000];
FILE *input_file, *output_alarm, *output_clear, *file_2MB;
int M_STAR;
int testptr;
char *teststr;
char *teststr1;
int STAR;
int ECP;
int AP;
int ACK_STAR;
int ACK_ECP;
int ACK_AP;
int file_pointer = 0;
int flag_2mb;
//while (1)
// {
input_file = fopen ("031209.APX", "r");
output_alarm = fopen ("rept_alarms.dat", "w+");
output_clear = fopen ("rept_clear.dat", "w+");
while (!feof (input_file))
{
M_STAR = 0;
STAR = 0;
AP = 0;
ECP = 0;
ACK_STAR = 0;
ACK_ECP = 0;
ACK_AP = 0;
fgets (rept_cell[0], 900, input_file);
printf("hi");
cell_alarm[0] = '\0';if ((strstr (rept_cell[0], "*") != NULL)
&& (strstr (rept_cell[0], "REPT:CELL") != NULL)
&& (strstr (rept_cell[0], "BOGGED") == NULL))
{
strcat (cell_alarm, rept_cell[0]);
cell_alarm[strlen (cell_alarm) - 1] = ';';
while (strstr (rept_cell[0], "/") == NULL)
{
fgets (rept_cell[0], 900, input_file);
if ((strstr(rept_cell[0],
"MEAS ERROR") == NULL) && (strstr (rept_cell[0], "CALLDROP") == NULL)&&
(strstr(rept_cell[0],"DBMISMATCH") == NULL))
STAR = 1;
{
if ((strchr (rept_cell[0], '\n') != NULL) && (strchr(rept_cell[0],'/') == NULL))
{
strcat (cell_alarm,
rept_cell[0]);
cell_alarm[strlen (cell_alarm) - 1] = ' ';
}
else if (strchr (rept_cell[0], '/') != NULL)
{
*rept_cell[0] = ';';
strcat (cell_alarm, rept_cell[0]);
}
}
}
}

if ((M_STAR == 1) || (STAR == 1) || (AP == 1))
fprintf (output_alarm, "%s", cell_alarm);
}
// }
fclose(input_file);
compiler is gcc
to run i use ./a.out

This is wrong because the first argument to fgets should be a char*, not char. I'm a little suprised the compiler didn't warn about that. If not, compile with -Wall.

please post code under [ code ] ... [ /code ] (without the spaces) in the future.

The problem is, you're not allocating space for rept_cell[0]. You have an array of 900 char * pointers and you're only using the first index in the array. I'd either change the definition char *rept_cell[900]; to just char rept_cell[900]; and then go through with Find and Replace to change every instance of rept_cell[0] to rept_cell or allocate memory for rept_cell[0]. I don't really see a need for the array of pointers in the code you pasted though. Best to drop the * from the definition and then Find and Replace like I mentioned. The fact that your fgets() call specifies a buffer size of 900 bytes makes me think that you didn't intend to create an array of pointers in the first place anyway.

EDIT: to aluser, rept_cell[0] is a char * in the code he pasted. That's why gcc allowed it. The problem is that rept_cell[0] just points to garbage.

gah my bad, I read it as char rept_cell[900] .. I should wake up first before posting