Help doing an e-mail program in c...

**Tyler_Durden** · 12-31-2004

Originally Posted by Sebastiani

>> ok..so the entire program until now is this:

I don't see progmail.h there.

sorry

progmail.h

Code:

#ifndef PROGMAIL_H_INCLUDED
#define PROGMAIL_H_INCLUDED
typedef struct mail
{
  char from[120];
  char to[120];
  char sub[120];
  char msg[120];
} MAIL;

typedef struct mailr
{
  char from[120];
  char to[120];
  char sub[120];
  char msg[120];
} MAILR;

void leficheiro(MAILR *m);
void comandom(MAIL *m);
void comandoC(MAIL *m);
void comandoL(MAIL *m);
#endif

**Emmanuel Delaha** · 12-31-2004

Originally Posted by Tyler_Durden

progmail.h
<...>

Why do you have two identical structure definitions ? A mail is a mail.
Unless you have planned some divergent evolution, you can remove the MAILR thing.

By the way, you don't need the tags.

One more detail, I suggest that the identifier used by the guard (here PROGMAIL_H_INCLUDED) begin with H_, hence H_PROGMAIL_xxx. The reason is that is prevents from using an identifier commencing with E. Those are reserved by the language for error numbers (ERANGE, EDOM etc.).

Try this (and fix your code consequently)

Code:

#ifndef H_PROGMAIL
#define H_PROGMAIL

/* progmail.h */

typedef struct
{
  char from[120];
  char to[120];
  char sub[120];
  char msg[120];
} MAIL;

void leficheiro(MAIL *m);
void comandom(MAIL *m);
void comandoC(MAIL *m);
void comandoL(MAIL *m);
#endif

[EDIT]
I have reread the thread, and I have seen that you have posted this

Code:

#define MAX 120

typedef struct mailr{
  char from[MAX+1];
  char to[MAX+1];
  char sub[MAX+1];
  char msg[MAX+1];
}MAILR;

Why was there a copy in 'progmail.h'

Ther are 2 design rules that have to be printed into you brain:

- Definitions shall be unique
- An implementation shll include it's interface file

This means, by example, that in "comandoC.c", you should have

#include "progmail.h"

hence a double definition for MAILR. Remove it.

That said, I think the way the definition of MAILR was made in "comandoC.c" was more clever than in "progmail.h". Hence, I suggest this new version of progmail.h:

Code:

#ifndef H_PROGMAIL
#define H_PROGMAIL

/* progmail.h */

#define MAX 120

typedef struct
{
  char from[MAX+1];
  char to[MAX+1];
  char sub[MAX+1];
  char msg[MAX+1];
}MAIL;

void leficheiro(MAIL *m);
void comandom(MAIL *m);
void comandoC(MAIL *m);
void comandoL(MAIL *m);
#endif

**Tyler_Durden** · 01-01-2005

so there it is..
the extension is ".c" but rename it to ".zip" and all the files are there.. I dunno if it will give some errors that I didn't have because last time I worked in the program I forgot to save, so I made the alterations now in windows without testing....

**Sebastiani** · 12-31-2004

well, the way things are set up you can't really delete items very easily (since you're using a single structure as opposed to an array, linked list, etc.). to be honest, there's too much wrong with the code to come up with a simple fix - I'm afraid you're on your own there. not sure if this helps any but perhaps looking at a similar program might be useful.

Code:

struct info {
  char data[MAX+1];
  struct info * next;
 };

struct info * newInfo(const char * buffer) {
 struct info * info = (struct info*)malloc(sizeof(struct info));
 strncpy(info->data, buffer, MAX);
 info->next = NULL;
 return info;
 } 
 
void deleteInfoList(struct info ** list) {
 struct info * goner, * iterator = *list;
 while(iterator != NULL) {
  goner = iterator;
  iterator = iterator->next;
  free(goner);
  }
 *list = NULL;  
 }  
 
void readInfo(const char * filename, struct info ** list) {
 struct info * info, * iterator;
 char buffer[MAX+1];
 FILE * fp = fopen(filename, "r");
 if(fp != NULL) {
  deleteInfoList(list);
  while(fgets(buffer, MAX, fp)) {
   info = newInfo(buffer);
   if(*list == NULL) {
    *list = iterator = info;
    } else {
    iterator->next = info;
    iterator = iterator->next;
    }    
   }
  }
 }
 
void writeInfo(const char * filename, struct info * list) {
 FILE * fp = fopen(filename, "w");
 if(fp != NULL) {
  chsize(fileno(fp), 0);
  while(list != NULL) {
   fprintf(fp, "%s", list->data);
   list = list->next;
   }
  }
 }
 
void printInfo(struct info * list) {
 int index = 1;
 printf(" ***** Database *****\n");
 while(list != NULL) {
  printf(" %d) %s", index++, list->data);
  list = list->next;
  }
 printf("\n"); 
 } 
 
void deleteInfo(struct info ** list) {
 char temp[MAX];
 unsigned which, index = 1;
 struct info * iterator, * prev = NULL;
 printf(" Enter the item # to delete: ");
 which = atoi(fgets(temp, MAX, stdin));
 for(iterator = *list; iterator != NULL; prev = iterator, iterator = iterator->next, ++index) {
  if(index == which) {
   if(prev != NULL) {
    prev->next = iterator->next;
    } else {
    *list = iterator->next; 
    } 
   free(iterator);
   break; 
   }
  } 
 } 
 
void addInfo(struct info ** list) {
 char buffer[MAX+1];
 struct info * info, * iterator = *list;
 printf(" Enter the new data: ");
 fgets(buffer, MAX, stdin);
 info = newInfo(buffer);
 if(*list == NULL) {
  *list = info;
  } else {
  while(iterator->next) {
   iterator = iterator->next;
   }  
  iterator->next = info; 
  } 
 }  
 
int menu(void) {
 int ch;
 char buffer[MAX+1];
  printf(
  " ***** Main Menu *****\n"
  " a) Add Info\n"
  " d) Delete Info\n"
  " p) Print Info\n"
  " x) Exit\n" 
  );
 ch = tolower(fgets(buffer, MAX, stdin)[0]); 
 printf("\n"); 
 return ch;
 } 
 
int main() {
 const char * file = "info.txt";
 struct info * list = NULL;
 int choice;
 readInfo(file, &list);
 while((choice = menu()) != 'x') {
  switch(choice) {
   case 'p' : 
    printInfo(list); 
    break;
   case 'a' : 
    addInfo(&list);
    writeInfo(file, list);
    break;
   case 'd' :
    deleteInfo(&list);
    writeInfo(file, list);
    break;
   default:
    printf("Invalid Selection\n");   
   }
  }
 return 0; 
 }

**Tyler_Durden** · 12-31-2004

I'm now going to try this program you gave me to see what I can do but could you just help me with the problem I'm having passing from the file to a struct... It is eliminating some letters...when passing from the file to the struct it goes from this:
From: bla bla
To: bla bla
Subject:bla bla
Message: bla bla

(to this)
From: bla bla
o: bla bla
bject:bla bla
sage: bla bla

**Tyler_Durden** · 12-31-2004

thanks for your tips ... =)
I need to different structs because I have to deal differently with the mails that are input, and the ones read from the file....
I only have a question.I've been able to do the leficheiro.c, that is the command that reads the file into a struct but it only works with one e-mail.. I need it to be able to read more e-mails (10, for example) and give them different names and variables..for example mail1, would have sub1,to1,from1,msg1 ..mail 2 would have to2,from2,subject2,etc... If I can do that then I will be able to present the info in the screen , and delete mails, etc...coudl you help me with this task?
my leficheiro.c is like this until now:

Code:

#include <stdio.h>
#include <string.h>
#include "progmail.h"

void leficheiro(MAILR *ptr)
{
  FILE *fp;

fp = fopen("mail.txt","r");

 fgets(ptr->to,50,fp);
 fgets(ptr->from,50,fp);
 fgets(ptr->sub,50,fp);
 fgets(ptr->msg,50,fp);
 fclose(fp);

}

thanks a lot and sorry for the bother.

EDIT - I knwo I need to make a loop and all that, and I tried, but can't figure out how to give the different names to each mail's variables..

**caroundw5h** · 12-31-2004

if you want to have more than one struct to use. simply make an array of structs. Say you have a structure.

Code:

#define NUM[100];
struct mail{
char person[NUM];
char name[NUM];
char addy[NUM];
char whatever[NUM];
};

/*make an arrray of 100 structs. */
struct mail MAILNUM[NUM];


/*to call each field in the struct */
MAILNUM[1].person = "harry";
MAILNUM[2].person = "tyler";

etc...

also

From: bla bla
To: bla bla
Subject:bla bla
Message: bla bla

(to this)
From: bla bla line 0
o: bla blap line 1
bject:bla bla line 2
sage: bla bla line 3

do you notice a pattern here? for each call to fgets it seems to print from that linenum.
ex: line 0 prints from 0, line 1 prints from 1 etc...

[edit] I notice you were up early in the morning doing this. I hope you get a decent grade. if you're really interested in learing C. Take a look here. you can get your feet wet. [/edit]

**Tyler_Durden** · 12-31-2004

Yes, I've been doing this intensively but I don't know if it is enough to get a positive grade =\
Now I will implement this technique to have numerous arrays to see if I can get what I want..hehe....
appreciated...

**Emmanuel Delaha** · 12-31-2004

Originally Posted by Tyler_Durden

Now I will implement this technique to have numerous arrays to see if

It's not 'numerous arrays'. It's ONE array of numerous structures.

**Tyler_Durden** · 01-02-2005

Bump...

Just this last help, guys... I only need to solve the segmentation fault error, and the rest is easy...the program is in the post abose, and the segmentation fault error happens when main trys to run leficheiro...

**Salem** · 01-01-2005

It's probably a good idea to ZIP all your source files and header files, then attach that single zip file to a post.

**itsme86** · 01-02-2005

You're passing mailr, a single instance of a MAILR struct, to leficheiro. But then in leficheiro you're trying to use it as an array. You can't do that.

**Tyler_Durden** · 01-02-2005

Originally Posted by itsme86

You're passing mailr, a single instance of a MAILR struct, to leficheiro. But then in leficheiro you're trying to use it as an array. You can't do that.

so can you please tell me what to change in the code to solve the error? I would be really thankful

**jverkoey** · 01-02-2005

In quite a few places, you are using the MAIL or the MAILR structure as if it is a variable, when it is not.

For example, in leficheiro.c, the lines 13-17, you use this following code:

Code:

 fgets("MAILR[i].to",120,fp);
 fgets("MAILR[i].from",120,fp);
 fgets("MAILR[i].sub",120,fp);
 fgets("MAILR[i].msg",120,fp);
fgets("MAILR[i].spc",120,fp);

Where it SHOULD be using the ptr variable. Also, when using variables, you don't put them inside quotes as you have. The compilable, working code should look like this:

Code:

 fgets(ptr[i].mail.to,120,fp);
 fgets(ptr[i].mail.from,120,fp);
 fgets(ptr[i].mail.sub,120,fp);
 fgets(ptr[i].mail.msg,120,fp);

I got rid of the .spc value in there as I didn't find an spc variable anywhere....

But that is basically your problem, that same thing occurs elsewhere in the program, you just need to remember to get rid of the quotes and make sure you are pointing to the correct values.

MAILR is an array of MAIL, therefor any MAILR variable should look like so:

Code:

MAILR variable;
variable[0].mail.<place variable here>

That is rough pseudocode, but you should see what I mean.

Also, you do not need to pass a pointer to a MAILR variable, as I noticed you do in one of the functions you use MAILR[] which isn't necessary, as the MAILR structure is already declared as an array, which in itself is a pointer. So it's best to remove the [] and also the MAILR *ptr in the declaration of the function.

Hopefully this clears a bit up, I have a working, compileable version of the code, but I want to see if you can fix it yourself.

**Tyler_Durden** · 01-02-2005

Originally Posted by jverkoey

In quite a few places, you are using the MAIL or the MAILR structure as if it is a variable, when it is not.

For example, in leficheiro.c, the lines 13-17, you use this following code:

Code:

 fgets("MAILR[i].to",120,fp);
 fgets("MAILR[i].from",120,fp);
 fgets("MAILR[i].sub",120,fp);
 fgets("MAILR[i].msg",120,fp);
fgets("MAILR[i].spc",120,fp);

Where it SHOULD be using the ptr variable. Also, when using variables, you don't put them inside quotes as you have. The compilable, working code should look like this:

Code:

 fgets(ptr[i].mail.to,120,fp);
 fgets(ptr[i].mail.from,120,fp);
 fgets(ptr[i].mail.sub,120,fp);
 fgets(ptr[i].mail.msg,120,fp);

I got rid of the .spc value in there as I didn't find an spc variable anywhere....

But that is basically your problem, that same thing occurs elsewhere in the program, you just need to remember to get rid of the quotes and make sure you are pointing to the correct values.

MAILR is an array of MAIL, therefor any MAILR variable should look like so:

Code:

MAILR variable;
variable[0].mail.<place variable here>

That is rough pseudocode, but you should see what I mean.

Also, you do not need to pass a pointer to a MAILR variable, as I noticed you do in one of the functions you use MAILR[] which isn't necessary, as the MAILR structure is already declared as an array, which in itself is a pointer. So it's best to remove the [] and also the MAILR *ptr in the declaration of the function.

Hopefully this clears a bit up, I have a working, compileable version of the code, but I want to see if you can fix it yourself.

i changed my leficheiro.c like you said but when compiling it gives me this error for lines 13-17
-> request for member "MAILR" in something not a structure or union

and like you say in the end of your post, how should I declare then the functions?