xv6/ulib.c

#include "types.h"
#include "stat.h"
#include "fcntl.h"
#include "user.h"
#include "x86.h"

char*strcpy(char *s, const char *t) {
    char *os;

    os = s;
    while ((*s++ = *t++) != 0) {
        ;
    }
    return os;
}

int strcmp(const char *p, const char *q) {
    while (*p && *p == *q) {
        p++, q++;
    }
    return (uchar) * p - (uchar) * q;
}

uint strlen(const char *s)      {
    int n;

    for (n = 0; s[n]; n++) {
        ;
    }
    return n;
}

void* memset(void *dst, int c, uint n) {
    stosb(dst, c, n);
    return dst;
}

char* strchr(const char *s, char c) {
    for (; *s; s++) {
        if (*s == c) {
            return (char*)s;
        }
    }
    return 0;
}

char* gets(char *buf, int max) {
    int i, cc;
    char c;

    for (i = 0; i + 1 < max;) {
        cc = read(0, &c, 1);
        if (cc < 1) {
            break;
        }
        buf[i++] = c;
        if (c == '\n' || c == '\r') {
            break;
        }
    }
    buf[i] = '\0';
    return buf;
}

int stat(const char *n, struct stat *st) {
    int fd;
    int r;

    fd = open(n, O_RDONLY);
    if (fd < 0) {
        return -1;
    }
    r = fstat(fd, st);
    close(fd);
    return r;
}

int atoi(const char *s) {
    int n;

    n = 0;
    while ('0' <= *s && *s <= '9') {
        n = n * 10 + *s++ - '0';
    }
    return n;
}

void* memmove(void *vdst, const void *vsrc, int n) {
    char *dst;
    const char *src;

    dst = vdst;
    src = vsrc;
    while (n-- > 0) {
        *dst++ = *src++;
    }
    return vdst;
}


__attribute__((noreturn))
int _init(int argc, char* argv[]) {
	main(argc, argv);
	exit();
}