Thread: Escape sequence search

Hey all,

I believe I have a very basic question for you all.. But I have tried and tried and cant get it to work to save my life.. I am wanting to return the index of the first '\n' that appears in a string. The escape sequence search is carried out in the sub function below.. The entire function (to read file line by line) is below also..

I am trying to get the string "aaa\nbbb\nccc" to return 4 (the position of the first '\n'....... Any idea why it isnt stopping?!

The sub function is :

Code:

static int        check_line(char *str)
{
        int i;

        i = 0;
        while (str)
        {
        printf("i is %d\n", i);
                if (str[i] == '\n')
                        return (i);
                i++;
        }
        return (0);
}

My entire function code is :

Code:

#include "line_by_line.h"
#include <stdio.h>

static int        check_line(char *str)
{
        int i;

        i = 0;
        while (str)
        {
        printf("i is %d\n", i);
                if (str[i] == '\n')
                        return (i);
                i++;
        }
        return (0);
}

static char        *ft_trim_line(char *str)
{
        char    *ret;
        int        i;

        i = 0;
        while (str[i] != '\n')
                i++;
        ret = ft_strnew(i);
        i = 0;
        while (str[i] != '\n')
        {
                ret[i] = str[i];
                i++;
        }
        ret[i] = '\0';
        return (ret);
}

static char        *ft_get_remainder(char *str)
{
        int        i;
        char    *ret;
        i = 0;

        while (str[i] != '\n')
                i++;
        ret = ft_strsub(str, i + 1, ft_strlen(str) - 1); 
        return (ret);
}

int            gl(const int fd, char **line)
{
        char buf[BUFF_SIZE + 1];
        static char *str;
        char *tmp;
        ssize_t ret;
        int index;

        if (BUFF_SIZE < 1 || !line || (fd < 0))
                return (-1);
        index = 0;
        if (!str)
                str = ft_memalloc(1);
        while ((ret = read(fd, buf, BUFF_SIZE)) > 0)
        {
                if (ret == -1)
                        return (-1);
                buf[BUFF_SIZE] = '\0';
                str = ft_strjoin(str, buf);
                if ((index = check_line(str)) != BUFF_SIZE)
                {
                        *line = ft_trim_line(str);
                        tmp = ft_strdup(str);
                        ft_strclr(str);
                        str = ft_strnew(BUFF_SIZE - index);
                        str = ft_get_remainder(tmp);
                        return(1);
                }
        }
        return (0);
}

A few thoughts:
* in your example "aaa\nbbb\nccc" the position of the \n is 4 so the correct index is 3 - remember it's zero-based.

* why return 0 when there is no \n , 0 is a valid index

An easier way

Code:

/* returns the index of ch in str or -1 if not found 
    usage: int res = indexof("Hello world", ' '); if (res == -1) handle not found
*/
int indexof(const char *str, char ch)
{
  int i;
  for (i = 0; str[i] != '\0'; i++)
    if (str[i] == ch)
      return i;

  return -1;
}