Update MentOs code to the latest development version.
This commit is contained in:
Enrico Fraccaroli
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/// @file stdio.c
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/// @brief Standard I/0 functions.
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/// @date Apr 2019
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#include <sys/errno.h>
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#include "stdio.h"
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#include "ctype.h"
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#include "string.h"
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#include "stdbool.h"
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#include "sys/unistd.h"
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void putchar(int character)
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{
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write(STDOUT_FILENO, &character, 1);
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}
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void puts(char *str)
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{
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write(STDOUT_FILENO, str, strlen(str));
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}
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int getchar(void)
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{
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char c;
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while (read(STDIN_FILENO, &c, 1) == 0)
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continue;
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return c;
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}
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char *gets(char *str)
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{
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// Check the input string.
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if (str == NULL)
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return NULL;
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// Buffer for reading input.
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char buffer[GETS_BUFFERSIZE];
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memset(buffer, '\0', GETS_BUFFERSIZE);
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// Char pointer to the buffer.
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char *cptr = buffer;
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// Character storage and counter to prevent overflow.
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int ch, counter = 0;
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// Read until we find a newline or we exceed the buffer size.
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while (((ch = getchar()) != '\n') && (counter++ < GETS_BUFFERSIZE)) {
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// If we encounter EOF, stop.
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if (ch == EOF) {
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// EOF at start of line return NULL.
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if (cptr == str) {
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return NULL;
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}
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break;
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}
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// Backspace key
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if (ch == '\b') {
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if (counter > 0) {
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counter--;
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--cptr;
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putchar('\b');
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}
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} else {
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// The character is stored at address, and the pointer is incremented.
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*cptr++ = ch;
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}
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}
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// Add the null-terminating character.
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*cptr = '\0';
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// Copy the string we have read.
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strcpy(str, buffer);
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// Return a pointer to the original string.
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return str;
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}
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int atoi(const char *str)
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{
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// Check the input string.
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if (str == NULL)
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return 0;
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// Initialize sign, the result variable, and two indices.
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int sign = (str[0] == '-') ? -1 : +1, result = 0, i;
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// Find where the number ends.
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for (i = (sign == -1) ? 1 : 0; (str[i] != '\0') && isdigit(str[i]); ++i)
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result = (result * 10) + str[i] - '0';
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return sign * result;
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}
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long strtol(const char *str, char **endptr, int base)
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{
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const char *s;
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long acc, cutoff;
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int c;
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int neg, any, cutlim;
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/*
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* Skip white space and pick up leading +/- sign if any.
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* If base is 0, allow 0x for hex and 0 for octal, else
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* assume decimal; if base is already 16, allow 0x.
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*/
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s = str;
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do {
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c = (unsigned char)*s++;
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} while (isspace(c));
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if (c == '-') {
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neg = 1;
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c = *s++;
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} else {
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neg = 0;
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if (c == '+')
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c = *s++;
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}
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if ((base == 0 || base == 16) &&
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c == '0' && (*s == 'x' || *s == 'X')) {
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c = s[1];
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s += 2;
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base = 16;
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}
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if (base == 0)
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base = c == '0' ? 8 : 10;
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/*
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* Compute the cutoff value between legal numbers and illegal
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* numbers. That is the largest legal value, divided by the
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* base. An input number that is greater than this value, if
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* followed by a legal input character, is too big. One that
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* is equal to this value may be valid or not; the limit
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* between valid and invalid numbers is then based on the last
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* digit. For instance, if the range for longs is
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* [-2147483648..2147483647] and the input base is 10,
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* cutoff will be set to 214748364 and cutlim to either
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* 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
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* a value > 214748364, or equal but the next digit is > 7 (or 8),
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* the number is too big, and we will return a range error.
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*
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* Set any if any `digits' consumed; make it negative to indicate
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* overflow.
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*/
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cutoff = neg ? LONG_MIN : LONG_MAX;
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cutlim = cutoff % base;
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cutoff /= base;
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if (neg) {
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if (cutlim > 0) {
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cutlim -= base;
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cutoff += 1;
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}
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cutlim = -cutlim;
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}
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for (acc = 0, any = 0;; c = (unsigned char)*s++) {
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if (isdigit(c))
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c -= '0';
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else if (isalpha(c))
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c -= isupper(c) ? 'A' - 10 : 'a' - 10;
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else
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break;
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if (c >= base)
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break;
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if (any < 0)
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continue;
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if (neg) {
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if (acc < cutoff || (acc == cutoff && c > cutlim)) {
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any = -1;
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acc = LONG_MIN;
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errno = ERANGE;
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} else {
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any = 1;
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acc *= base;
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acc -= c;
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}
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} else {
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if (acc > cutoff || (acc == cutoff && c > cutlim)) {
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any = -1;
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acc = LONG_MAX;
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errno = ERANGE;
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} else {
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any = 1;
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acc *= base;
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acc += c;
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}
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}
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}
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if (endptr != 0)
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*endptr = (char *)(any ? s - 1 : str);
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return (acc);
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}
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int fgetc(int fd)
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{
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unsigned char c;
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if (read(fd, &c, 1) <= 0)
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return EOF;
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return c;
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}
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char *fgets(char *buf, int n, int fd)
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{
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int c;
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char *p;
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/* get max bytes or upto a newline */
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for (p = buf, n--; n > 0; n--) {
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if ((c = fgetc(fd)) == EOF)
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break;
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*p++ = c;
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if (c == '\n')
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break;
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}
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*p = 0;
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if (p == buf || c == EOF)
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return NULL;
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return (p);
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}
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