Reading from ext file

AMMullan · 01-23-2004, 04:41 PM

I'm doing a favor for a mate and trying to get an app made for him... So i'm making him a little C app to do it...

What I need to know is how I would read a variable from external file i.e.

Code:

Settings.ini:

NAME = foo

then in the actual main prog i wanna read the argument:

Code:

#include <stdio.h>
#include "Settings.ini"

int main() {
  char name[128];

  printf("Name = %s", name);
  return 0;
}

I know about using headers but this is going to be run under windoze

So i'd want it to be an ini file...

Thanx in advance

itsme86 · 01-23-2004, 05:18 PM

I actually wrote a little app that did this exact thing. Here's an exerpt:

Code:

char **drives = NULL;
char *destination = NULL;
char **folders = NULL;
char **extensions = NULL;
char **exclusions = NULL;
int ndrives = 0;
int nfolders = 0;
int nextensions = 0;
int nexclusions = 0;

int change_section(char *str)
{
  if(!strcmpi(str, "[Drives]"))
    return 1;
  if(!strcmpi(str, "[Destination]"))
    return 2;
  if(!strcmpi(str, "[Folders]"))
    return 3;
  if(!strcmpi(str, "[Extensions]"))
    return 4;
  if(!strcmpi(str, "[Exclusions]"))
    return 5;
  return 0;
}

void load_ini(void)
{
  FILE *fp;
  char buf[4096], *b, **dest;
  int line = 0, section = 0;

  if(!(fp = fopen("settings.ini", "r")))
  {
    fprintf(stderr, "Couldn't open \"settings.ini\" for reading!\n");
    exit(1);
  }

  while(fgets(buf, sizeof(buf), fp))
  {
    if(feof(fp))
      break;

    line++;
    b = &buf[strlen(buf)-1];
    while(*buf && (!isprint(*b) || isspace(*b)))
      *b-- = '\0';
    b = buf;
    while(isspace(*b))
      b++;
    if(!*b || *b == '#')
      continue;

    if(*b == '[')
    {
      section = change_section(b);
      continue;
    }

    switch(section)
    {
      case 1:
        if(ndrives)
          drives = realloc(drives, sizeof(char *)*(ndrives+1));
        else
          drives = malloc(sizeof(char *));
        dest = &drives[ndrives++];
        break;
      case 2:
        if(destination)
          free(destination);
        dest = &destination;
        break;
      case 3:
        if(nfolders)
          folders = realloc(folders, sizeof(char *)*(nfolders+1));
        else
          folders = malloc(sizeof(char *));
        dest = &folders[nfolders++];
        break;
      case 4:
        if(nextensions)
          extensions = realloc(extensions, sizeof(char *)*(nextensions+1));
        else
          extensions = malloc(sizeof(char *));
        dest = &extensions[nextensions++];
        break;
      case 5:
        if(nexclusions)
          exclusions = realloc(exclusions, sizeof(char *)*(nexclusions+1));
        else
          exclusions = malloc(sizeof(char *));
        dest = &exclusions[nexclusions++];
        break;
      default:
        fprintf(stderr,
          "Line %d: Found setting outside of section header.\n", line);
        fclose(fp);
        exit(1);
    }

    *dest = malloc(strlen(b)+1);
    strcpy(*dest, b);
  }

  if(!destination)
  {
    fprintf(stderr, "No destination drive was specified.\n");
    exit(1);
  }

  fclose(fp);
}

Then you can simply call load_ini() and viola. Here's an example of the ini file that this program uses:

Code:

# Lines beginning with a hashmark (#) are considered to be comments and 
# are ignored. Blank lines are also ignored.

# --- Configuration Begins ---

# List of drives to search on the PC. Drives that don't exist will simply 
# be ignored. Do NOT include the trailing blackslash (\)

[Drives]
C:
# D:
# E:

# The folder to copy all the found files to. If the folder doesn't exist 
# when the program starts, it will automatically be created. If 
# multiple folders are listed, ONLY the last one will be used. Do NOT 
# include the trailing backslash (\)

[Destination]
C:\User

I hope that answers your question anyway

AMMullan · 01-23-2004, 09:27 PM

Can ya post the main() section aswell...

deiussum · 01-26-2004, 08:34 AM

If you are doing it in Windows, why not use the Win32 APIs for reading ini files. The APIs you will want to look at are the [Get/Write]PrivateProfile* functions.

AMMullan · 01-26-2004, 11:12 AM

To be honest, didn't know anything about the windoze API's...

I'm not looking to get into Windoze programming - thought I could use the knowledge that I have so far to do it as i'm still learning C on Linux and don't wanna confuse it ny taking months to learn windoze API's etc, let alone keep my PC in windoze when i don't have to

Cheers anyway