Warnings and segmentation fault core dumped - c

Question

This is a program to remove particular lines in a file. It copies the lines which are needed and prints it in another file in the same directory. I'm not getting any errors except for warnings such as incompatible pointer type [-Wincompatible-pointer-types]. When I run the code I also get the prtintf statement but when entered input Segmentation fault (core dumped). Is it related to the warnings or is it something else ?
code
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<stdbool.h>
#include <ctype.h>
char *name_find(char *buf[], char *name[]) {
const char *p = NULL;
size_t len = strlen(name);
if (len > 0) {
for (p = buf ; (p = strstr(p, name)) != NULL; p++) {
if (p == buf || !isalnum((unsigned char)p[-1])) {
if (!isalnum((unsigned char)p[len]))
break; /* we have a match! */
p += len; /* next match is at least len+1 bytes away */
}
}
}
return p;
}
int main()
{
char name[25];
char buf[100];
setenv("PFILE","/home/ashwin/Desktop/FILE/",1);
char ori_path[100],new_path[100];
if (!getenv("PFILE")){
}
else{
strcpy(ori_path, getenv("PFILE"));
strcpy(new_path, getenv("PFILE"));
strcat(ori_path, "shadow");
strcat(new_path, "shadow1");
}
bool success=false;
printf("Enter the command\n ");
printf("userdel ");
FILE *fold = fopen(ori_path, "r"); // old file
FILE *fnew = fopen(new_path, "w"); // new temp file
fgets(name,25,stdin);
for(int i = 0; i < strlen(name); i++)
{
if(name[i] == '\n')
{
name[i] = '\0';
break;
}
}
while (fgets(buf, 100, fold)) {
// read lines until error or EOF
if (!name_find(buf, name)) {
fprintf(fnew, "%s", buf);
success=true;
}
}
if(success){
printf("Success !!!\n");
}
return 0;
}

Answer 1

char *name_find(char *buf[], char *name[])
You use char *buf[], which means buf is an array of pointers to char, not a pointer to char. Use char* buf instead. Same goes for name.
Additionally:
FILE *fold = fopen(ori_path, "r"); // old file
FILE *fnew = fopen(new_path, "w"); // new temp file
You should check if the opening of the streams to the files were successful by checking the returned pointers for a null pointer:
FILE *fold = fopen(ori_path, "r"); // old file
if(!fold)
{
fputs("Error at opening fold!", stderr);
exit(1);
}
FILE *fnew = fopen(new_path, "w"); // new temp file
if(!fnew)
{
fputs("Error at opening fnew!", stderr);
exit(1);
}
Try this code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <ctype.h>
char *name_find(char *buf, char *name) {
const char *p = NULL;
size_t len = strlen(name);
if (len > 0) {
for (p = buf ; (p = strstr(p, name)) != NULL; p++) {
if (p == buf || !isalnum((unsigned char)p[-1])) {
if (!isalnum((unsigned char)p[len]))
break; /* we have a match! */
p += len; /* next match is at least len+1 bytes away */
}
}
}
return p;
}
int main (void)
{
char name[25];
char buf[100];
setenv("PFILE","/home/ashwin/Desktop/FILE/",1);
char ori_path[100],new_path[100];
if (!getenv("PFILE")){
}
else{
strcpy(ori_path, getenv("PFILE"));
strcpy(new_path, getenv("PFILE"));
strcat(ori_path, "shadow");
strcat(new_path, "shadow1");
}
bool success=false;
printf("Enter the command\n ");
printf("userdel ");
FILE *fold = fopen(ori_path, "r"); // old file
if(!fold)
{
fputs("Error at opening fold!", stderr);
exit(1);
}
FILE *fnew = fopen(new_path, "w"); // new temp file
if(!fnew)
{
fputs("Error at opening fnew!", stderr);
exit(1);
}
fgets(name,25,stdin);
for(unsigned int i = 0; i < strlen(name); i++)
{
if(name[i] == '\n')
{
name[i] = '\0';
break;
}
}
while (fgets(buf, 100, fold)) {
// read lines until error or EOF
if (!name_find(buf, name)) {
fprintf(fnew, "%s", buf);
success=true;
}
}
if(success){
printf("Success !!!\n");
}
return 0;
}