Hi all,
In my function, the while loop is not terminating when it should so when the code within that while loop is called, the program stops prematurely because of a Segmentation fault.
This program is used to create directory structures tree of depth d and breadth b which come from argv and works for the 1st and 2nd iteration of the outside for loop but it does not go to the 3rd iteration because it continues through the while loop of the 2nd iteration.
P.S. what's also strange is that the program works fine for smaller depth and breadth so could this be a problem with my system's memory allocation possibly?
Declarations and main function..
problem functionCode:#include <stdio.h> #include <malloc.h> #include <string.h> #include <stdlib.h> #include <math.h> #define MAXD 10 /* 3 <= depth < MAXD */ #define MAXB 10 /* 3 <= breadth < MAXB */ void create_dir_tree(); void traverse_dir_tree(); int find_total_no_dirs(); int find_dir(); struct dir { char *path; /* path to get to this dir, not including this */ char *name; /* current dir name */ int d; /* 3 <= depth level < MAXD */ /* the init_d is depth 0, its immediate subdirs are depth 1, etc. */ int b; /* 3 <= breadth or number of sub dirs < MAXB */ struct dir *up; /* points to the parent */ struct dir **down; /* points to the sub dirs of this dir. Note the TWO *'s */ struct dir *left; /* left sibling dir, use circular link */ struct dir *right; /* right sibling dir, use circular link */ }; int main(int argc, char **argv) { struct dir *hp; int b,d,n,flag; char *init_d,tst_dir[100]; if (argc < 4) { printf("usage: hw3 root_d d b\n"); return 1; } argv++; /* skip the command itself */ init_d = *(argv++); d = atoi(*argv++); b = atoi(*argv++); create_dir_tree(&hp,init_d,d,b); if ((flag = find_dir(hp,tst_dir))) printf("dir %s found\n",tst_dir); else printf("no dir %s found\n",tst_dir); return 0; }
Code:/* create directories breadth first */ void create_dir_tree(struct dir **hp,char *name,int d, int b) { printf("create_dir_tree init_d=%s depth=%d breadth=%d\n",name,d,b); /* fill in here */ struct dir *cp; struct dir *tmp; struct dir **newopen=malloc(sizeof(struct dir*)); struct dir **open; struct dir **closed=malloc(sizeof(struct dir*)); int count = 0; int ccounter=0; int counter = 0; char *buffer=malloc(3); char *buff; if(!buffer||!buff) return; cp=(*hp); cp=malloc(sizeof(struct dir)); cp->name = name; cp->path = "\0"; cp->d = 0; cp->b = 1; cp->up = NULL; cp->left = NULL; cp->right = NULL; *newopen= cp; int i; for(i = 0; i < d ; i++){ open=newopen; printf("First element of newopen: %s%s\n",(*newopen)->path,(*newopen)->name); printf("Malloc %d^%d or %f structs for newopen\n", b,i+1,pow(b,i+1)); newopen=malloc(pow(b,i+1)*sizeof(struct dir*)); count = 0; counter = 0; closed = realloc(closed, ccounter * sizeof(struct dir*)+1); while(open[0]){ //bug during i=1 after the while loop should be done //=> suppose to fail to go to i=2 but continues here anyway making any reference to open[0] or *open causes segment fault printf("Start of while loop\n"); printf("Expanding %s%s\n",(*open)->path,(*open)->name); cp = *open; printf("passed the error\n"); cp->down=malloc(b * sizeof(struct dir*)); count=counter; int j; for(j = 0; j < b; j++,counter++){ tmp = malloc(sizeof(struct dir)); buff=malloc(3); newopen[j+count]=tmp; tmp->up=cp; tmp->path=realloc(tmp->path,strlen(tmp->up->path)+strlen(tmp->up->name)+1); strcpy(tmp->path,tmp->up->path); strcat(tmp->path,tmp->up->name); tmp->name=malloc(4); *buff='/'; sprintf(buffer,"%d", j); strcat(buff,buffer); tmp->name=realloc(tmp->name,strlen(tmp->name)+strlen(buff)+1); strcat(tmp->name,buff); printf("Creating Directory: %s%s\n",tmp->path,tmp->name); cp->down[j]=tmp; if(j==(b-1)){ cp->down[j]->right=cp->down[0]; cp->down[0]->left=cp->down[j]; } else if (j>0){ cp->down[j-1]->right=cp->down[j] ; } } printf("Just expanded: %s%s and appending to closed\n",(*open)->path,(*open)->name); closed[ccounter++]=*open; open++; printf("%s\n","End of While Loop"); } } }
Originally Posted by workisnotfun
