Seg Fault

[HighSeraphim]

I'm getting a seg-fault in the following code: strcat seems to be throwing the fault.
I don't understand why that is the case because I am putting strings into both arguments

struct procinfo { char *file; char *info;};

int procSize = 3;
int procCount= 0;
char *file = "1.txt";
FILE *fp;


struct procinfo procs[] = {
    "status", "Pid",
    "status", "PPid",
    "environ", "USER=",
};


int main(void){

  DIR           *d;
  struct dirent *dir;

  if (chdir("/proc")!=0)
    printf("Directory Not Found Properly"); //Set current directory to /proc

  d = opendir(".");

  if (d){
    while ((dir = readdir(d)) != NULL){
        procCount = 0;
        if(isdigit(dir->d_name[0])){//If directory starts with a number
            printf("PROCESS: %s\n", dir->d_name);  
          
            while(procCount < procSize){
                file = "/proc/";
                strcat(file, dir->d_name);
                printf("%s\n = file", file);

[quzah]

Is there some place here where you actually allocate memory? Because I'm not seeing it.


Quzah.

[HighSeraphim]

nope... so I have to Malloc the string File then? I always get confused about when I have to Malloc and when I don't.

[tabstop]

"/proc/" is not a string that can be added to, as there is no additional space at the end of it for new characters.

[quzah]

nope... so I have to Malloc the string File then? I always get confused about when I have to Malloc and when I don't.

Any time you don't have a fixed variable/array that you're using, you need to allocate your own.


Quzah.

[HighSeraphim]

if that is the case /proc/\0 should work right? and that isn't the case

[HighSeraphim]

Thanks!

[tabstop]

if that is the case /proc/\0 should work right? and that isn't the case

That's what you have. And no, it's not something that can be added to, because there's (still) no room at the end. The string literal has just enough room for what you put inside the quotes, not any spare memory just because.