#define BUFFER_SIZE 42
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
size_t ft_strlen(const char *str)
{
int index;
index = 0;
while (str[index] != '\0')
{
index++;
}
return (index);
}
char *ft_strchr(const char *s, int c)
{
while (*s != '\0')
{
if (*s == c)
return ((char *)s);
s++;
}
if (*s == c)
return ((char *)s);
return (0);
}
char *ft_strdup(const char *s)
{
int i;
char *mem;
i = 0;
mem = (char *)malloc(sizeof(char) * (ft_strlen(s) + 1));
if (mem == NULL)
return (NULL);
while (*s != '\0')
{
mem[i] = *s;
i++;
s++;
}
mem[i] = '\0';
return (mem);
}
size_t ft_strlcpy(char *dst, const char *src, size_t size)
{
size_t n;
char *d;
const char *s;
d = dst;
s = src;
n = 0;
while (*s != '\0')
{
if (n + 1 < size)
{
*d = *s;
d++;
}
s++;
n++;
}
if (size)
*d = '\0';
return (n);
}
char *ft_strjoin(char const *s1, char const *s2)
{
char *mem;
int i;
int len;
i = 0;
len = ft_strlen(s1) + ft_strlen(s2);
mem = (char *)malloc(sizeof(*mem) * (len + 1));
if ((s1 == NULL || s2 == NULL) || mem == NULL)
return (NULL);
while (*s1 != '\0')
{
mem[i] = *s1++;
i++;
}
while (*s2 != '\0')
{
mem[i] = *s2++;
i++;
}
mem[i] = '\0';
return (mem);
}
char *ft_substr(char const *s, unsigned int start, size_t len)
{
char *mem;
size_t size;
size = ft_strlen(s);
if (start >= size)
return (ft_strdup(""));
if (len < size)
mem = (char *)malloc(sizeof(*mem) * len + 1);
else
mem = (char *)malloc(sizeof(*mem) * size - start + 1);
ft_strlcpy(mem, s + start, len + 1);
return (mem);
}
static char *get_line(char *line)
{
size_t start;
char *next_line;
start = 0;
while (line[start] != '\n' && line[start])
start++;
next_line = ft_substr(line, start + 1, ft_strlen(line) - start);
if (!*next_line)
{
free(next_line);
return (NULL);
}
line[start + 1] = '\0';
return (next_line);
}
static char *read_line(int fd, char *next_line, char *buffer)
{
int byte;
char *temp;
byte = 1;
while (byte != 0)
{
byte = read(fd, buffer, BUFFER_SIZE);
if (byte < 0)
return (NULL);
else if (byte == 0)
return (next_line);
buffer[byte] = '\0';
if (!next_line)
next_line = ft_strdup("");
temp = next_line;
next_line = ft_strjoin(temp, buffer);
free(temp);
if (ft_strchr(buffer, '\n'))
return (next_line);
}
return (next_line);
}
char *get_next_line(int fd)
{
char *line;
char *buffer;
static char *next_line;
if (fd < 0 || BUFFER_SIZE <= 0)
return (0);
buffer = (char *)malloc(sizeof(*buffer) * BUFFER_SIZE + 1);
if (!buffer)
return (0);
line = read_line(fd, next_line, buffer);
free(buffer);
if (!line)
return (NULL);
next_line = get_line(line);
return (line);
}
int main(void)
{
int fd;
fd = open("42file", O_RDONLY | O_CREAT, S_IRUSR, S_IWUSR);
if (fd == -1)
{
printf("File Error\n");
return (1);
}
printf("%s\n", get_next_line(fd));
if (close(fd) == -1)
{
printf("File Close Error\n");
return (1);
}
return (0);
} Write, Run & Share C Language code online using OneCompiler's C online compiler for free. It's one of the robust, feature-rich online compilers for C language, running the latest C version which is C18. Getting started with the OneCompiler's C editor is really simple and pretty fast. The editor shows sample boilerplate code when you choose language as 'C' and start coding!
OneCompiler's C online editor supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample C program which takes name as input and print your name with hello.
#include <stdio.h>
int main()
{
char name[50];
printf("Enter name:");
scanf("%s", name);
printf("Hello %s \n" , name );
return 0;
}
C language is one of the most popular general-purpose programming language developed by Dennis Ritchie at Bell laboratories for UNIX operating system. The initial release of C Language was in the year 1972. Most of the desktop operating systems are written in C Language.
When ever you want to perform a set of operations based on a condition if-else is used.
if(conditional-expression) {
// code
} else {
// code
}
You can also use if-else for nested Ifs and if-else-if ladder when multiple conditions are to be performed on a single variable.
Switch is an alternative to if-else-if ladder.
switch(conditional-expression) {
case value1:
// code
break; // optional
case value2:
// code
break; // optional
...
default:
// code to be executed when all the above cases are not matched;
}
For loop is used to iterate a set of statements based on a condition.
for(Initialization; Condition; Increment/decrement){
// code
}
While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.
while(condition) {
// code
}
Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.
do {
// code
} while (condition);
Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index. Index starts from 0 to size-1.
data-type array-name[size];
data-type array-name[size][size];
Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity.
Two types of functions are present in C
Library functions are the in-built functions which are declared in header files like printf(),scanf(),puts(),gets() etc.,
User defined functions are the ones which are written by the programmer based on the requirement.
return_type function_name(parameters);
function_name (parameters)
return_type function_name(parameters) {
//code
}