C programming Seg fault help
:frown:
I'm making a line editor(for a file) & up tp append function.(type in "a")
the append function is to append something after the current line.
im now getting seg fault but cant really find out what cause the problem
:frown:really frustrated
Code:
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#define NUMBERLINES 1000 // max number of lines that can be read
#define LINELENGTH 1000 // max length of a line
#define FNAMELENGTH 100 // max length of a file name
#define CMDLENGTH 102 // max length of a command (e.g.'f' + ' ' + filename)
typedef struct Node {
char line[LINELENGTH];
struct Node *next;
} NodeT;
NodeT* ScanInput(FILE *, char*, NodeT*);
void PrintCommand(void);
void PrintSpace(void);
NodeT *PrintAll(NodeT *);
NodeT *ReadFile(char *);
void Unknown(void);
void PrintCur(NodeT *);
NodeT *makeNode(char *);
NodeT *GotoB(NodeT* );
NodeT *ReadFirst(FILE *);
NodeT *DecP(NodeT *, char *);
NodeT *IncP(NodeT *, char *);
NodeT *Append(char *,NodeT *);
int main(int argc, char **argv) {
FILE *fp;
fp = NULL;
char filename[FNAMELENGTH];
NodeT *cur = NULL;
if(argc > 2){
printf("Usage: ./led [filename]\n");
exit(1);
}
if(argv != NULL){
strcpy(filename,argv[1]);
if((fp = fopen(filename,"r")) != NULL){
printf("Existing file\n");
cur = ReadFirst(fp);
fclose(fp);
}
else{
fp = fopen(filename,"w");
printf("Creating file %s\n", filename);
}
}
while(1) cur = ScanInput(fp, filename, cur);
return 0;
}
NodeT* ScanInput(FILE *s, char *argv, NodeT *cur){
char input[CMDLENGTH];
char filename[FNAMELENGTH];
NodeT *head = NULL;
NodeT *tmp = NULL;
char curline[LINELENGTH];
FILE *fp;
fp = NULL;
strcpy(filename,argv);
printf("? ");
fgets(input,CMDLENGTH,stdin);
if(strcmp(input,"h\n") == 0){
PrintCommand();
}
if(strcmp(input,"q\n") == 0){
exit(1);
}
if(strcmp(input,"p\n") == 0){
head = ReadFile(filename);
PrintAll(head);
cur = GotoB(head);
}
if(strcmp(input,"x\n") == 0){
printf("Forced exit, changes not saved\n");
exit(1);
}
if(strcmp(input,".\n") == 0){
PrintCur(cur);
}
if(strcmp(input,"-\n") == 0){
cur = DecP(cur,filename);
PrintCur(cur);
}
if((strcmp(input,"+\n") == 0) || (strcmp(input,"\n") == 0)){
cur = IncP(cur,filename);
PrintCur(cur);
}
if(strcmp(input,"a\n") == 0){
head = Append(filename,cur);
}
/*
if(strcmp(input,"f") == 0){
if(scanf("%s",filename) != 0) {
Unknown();
}
if((fp1 = fopen(filename,"r")) != NULL){
fclose(fp1);
printf("File %s already exist, saving will overwrite", filename);
}
else {
printf("Creating file :%s\n", filename);
fp1 = fopen(filename,"w");
}
}*/
return cur;
}
NodeT *ReadFirst(FILE *fp){
NodeT *tmp;
char line[LINELENGTH];
if(fgets(line, LINELENGTH , fp) != NULL){
tmp = makeNode(line);
}
return tmp;
}
NodeT *GotoB(NodeT* head){
NodeT *tmp;
tmp = head;
if(tmp == NULL){
return NULL;
}
while(tmp->next != NULL){
tmp = tmp -> next;
}
return tmp;
}
void PrintCur(NodeT *cur){
//if(cur == NULL) return ;
printf("%s",cur->line);
}
void PrintCommand(){
printf("Commands are (in upper or lower case):\n");
PrintSpace();
printf("q: quit\n");
PrintSpace();
printf("s: save\n");
PrintSpace();
printf("x: force exit\n");
PrintSpace();
printf("f <filename>: the file is called <filename>\n");
PrintSpace();
printf("h: print this help message\n");
PrintSpace();
printf("d: delete current line\n");
PrintSpace();
printf("a: append after current line, terminated by '.'\n");
PrintSpace();
printf("i: insert before current line, terminated by '.'\n");
PrintSpace();
printf("p: print all lines\n");
PrintSpace();
printf(".: print current line\n");
PrintSpace();
printf("+: increment line and print\n");
PrintSpace();
printf("<return>: same as '+'\n");
PrintSpace();
printf("-: decrement line and print\n");
PrintSpace();
printf("number: make 'number' the current line\n");
}
void PrintSpace(){
printf(" ");
}
void Unknown(){
printf("Unknown command: ignoring\n");
}
NodeT *PrintAll (NodeT *s) {
NodeT *cur;
int line = 1;
cur = s;
if(strcmp(cur->line,"\n") == 0) {
printf("Empty File\n");
return NULL;
}
while(cur != NULL) {
printf("LINE %d %s", line, cur->line);
cur = cur->next;
line++;
}
return cur;
}
NodeT *ReadFile(char *filename){
int i = 0;
char line [LINELENGTH ];
char *get;
FILE *fp;
fp = NULL;
NodeT *head;
NodeT *cur;
NodeT *new;
if((fp = fopen(filename,"r")) == NULL){
printf("Empty File\n");
printf("%s\n",filename);
return NULL;
}
if((get = fgets(line, LINELENGTH , fp)) != NULL) {
head = makeNode(line);
cur = head;
}
while (fgets(line, LINELENGTH , fp) != NULL) {
new = makeNode(line);
cur->next = new;
cur = new;
i++;
}
fclose(fp);
return head;
}
NodeT *Append(char *filename, NodeT *cur){
FILE *fp;
NodeT *head;
NodeT *tmp;
NodeT *inputhead;
NodeT *inputcur;
NodeT *inputnew;
NodeT *tmp1;
char line [LINELENGTH];
char c;
int i = 1,linenum = 1;
head = ReadFile(filename);
tmp = head;
fgets(line,LINELENGTH, stdin);
while(1){
fgets(line,LINELENGTH, stdin);
sscanf(line,"%c",&c);
if(c == '.') break;
if(i == 1){
inputhead = makeNode(line);
inputcur = inputhead;
}
else{
inputnew = makeNode(line);
inputcur->next = inputnew;
}
i++;
}
while(strcmp(tmp->line,cur->line) != 0 ){
tmp = tmp->next;
}
cur = tmp->next;
tmp->next = inputhead;
inputcur->next = cur;
fp = fopen(filename,"w+");
tmp1 = head;
while(tmp1 != NULL){
fprintf(fp,"%s",tmp1->line);
tmp1 = tmp1->next;
linenum++;
}
return head;
}
NodeT *makeNode(char *line) {
NodeT *new;
new = malloc(sizeof(NodeT));
if (new == NULL) {
exit(1);
}
strcpy(new->line,line);
new->next = NULL;
return new;
}
NodeT *DecP(NodeT *cur, char *filename){
NodeT *tmp;
if((tmp = ReadFile(filename)) == NULL){
printf("Empty File\n");
return NULL;
}
while(strcmp(tmp->next->line,cur->line) != 0){
tmp = tmp->next;
}
return tmp;
}
NodeT *IncP(NodeT *cur, char *filename){
NodeT *tmp;
if((tmp = ReadFile(filename)) == NULL){
printf("Empty File\n");
return NULL;
}
while(strcmp(tmp->line,cur->line) != 0){
tmp = tmp->next;
}
if(tmp->next == NULL) return tmp;
else return tmp->next;
}
