/*
 * Replacements for common but usually nonstandard functions that aren't
 * supplied by all platforms.
 *
 * Copyright (C) 2009 by Dan Fandrich <dan@coneharvesters.com>, et. al.
 *
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */
#include "libbb.h"

#ifndef HAVE_STRCHRNUL
char* FAST_FUNC strchrnul(const char *s, int c)
{
        while (*s != '\0' && *s != c)
                s++;
        return (char*)s;
}
#endif

#ifndef HAVE_USLEEP
int FAST_FUNC usleep(unsigned usec)
{
        struct timespec ts;
        ts.tv_sec = usec / 1000000u;
        ts.tv_nsec = (usec % 1000000u) * 1000u;
        /*
         * If a signal has non-default handler, nanosleep returns early.
         * Our version of usleep doesn't return early
         * if interrupted by such signals:
         */
        while (nanosleep(&ts, &ts) != 0)
                continue;
        return 0;
}
#endif

#ifndef HAVE_VASPRINTF
int FAST_FUNC vasprintf(char **string_ptr, const char *format, va_list p)
{
        int r;
        va_list p2;
        char buf[128];

        va_copy(p2, p);
        r = vsnprintf(buf, 128, format, p);
        va_end(p);

        /* Note: can't use xstrdup/xmalloc, they call vasprintf (us) on failure! */

        if (r < 128) {
                va_end(p2);
                *string_ptr = strdup(buf);
                return (*string_ptr ? r : -1);
        }

        *string_ptr = malloc(r+1);
        r = (*string_ptr ? vsnprintf(*string_ptr, r+1, format, p2) : -1);
        va_end(p2);

        return r;
}
#endif

#ifndef HAVE_DPRINTF
/* dprintf is now part of POSIX.1, but was only added in 2008 */
int dprintf(int fd, const char *format, ...)
{
        va_list p;
        int r;
        char *string_ptr;

        va_start(p, format);
        r = vasprintf(&string_ptr, format, p);
        va_end(p);
        if (r >= 0) {
                r = full_write(fd, string_ptr, r);
                free(string_ptr);
        }
        return r;
}
#endif

#ifndef HAVE_MEMRCHR
/* Copyright (C) 2005 Free Software Foundation, Inc.
 * memrchr() is a GNU function that might not be available everywhere.
 * It's basically the inverse of memchr() - search backwards in a
 * memory block for a particular character.
 */
void* FAST_FUNC memrchr(const void *s, int c, size_t n)
{
        const char *start = s, *end = s;

        end += n - 1;

        while (end >= start) {
                if (*end == (char)c)
                        return (void *) end;
                end--;
        }

        return NULL;
}
#endif

#ifndef HAVE_MKDTEMP
/* This is now actually part of POSIX.1, but was only added in 2008 */
char* FAST_FUNC mkdtemp(char *template)
{
        /* NB: on error, mktemp returns an empty string, not NULL */
        if (mktemp(template)[0] == '\0' || mkdir(template, 0700) != 0)
                return NULL;
        return template;
}
#endif

#ifndef HAVE_STRCASESTR
/* Copyright (c) 1999, 2000 The ht://Dig Group */
char* FAST_FUNC strcasestr(const char *s, const char *pattern)
{
        int length = strlen(pattern);

        while (*s) {
                if (strncasecmp(s, pattern, length) == 0)
                        return (char *)s;
                s++;
        }
        return 0;
}
#endif

#ifndef HAVE_STRSEP
/* Copyright (C) 2004 Free Software Foundation, Inc. */
char* FAST_FUNC strsep(char **stringp, const char *delim)
{
        char *start = *stringp;
        char *ptr;

        if (!start)
                return NULL;

        if (!*delim)
                ptr = start + strlen(start);
        else {
                ptr = strpbrk(start, delim);
                if (!ptr) {
                        *stringp = NULL;
                        return start;
                }
        }

        *ptr = '\0';
        *stringp = ptr + 1;

        return start;
}
#endif

#ifndef HAVE_STPCPY
char* FAST_FUNC stpcpy(char *p, const char *to_add)
{
        while ((*p = *to_add) != '\0') {
                p++;
                to_add++;
        }
        return p;
}
#endif

#ifndef HAVE_STPNCPY
char* FAST_FUNC stpncpy(char *p, const char *to_add, size_t n)
{
        while (n != 0 && (*p = *to_add) != '\0') {
                p++;
                to_add++;
                n--;
        }
        return p;
}
#endif

#ifndef HAVE_GETLINE
ssize_t FAST_FUNC getline(char **lineptr, size_t *n, FILE *stream)
{
        int ch;
        char *line = *lineptr;
        size_t alloced = *n;
        size_t len = 0;

        do {
                ch = fgetc(stream);
                if (ch == EOF)
                        break;
                if (len + 1 >= alloced) {
                        alloced += alloced/4 + 64;
                        line = xrealloc(line, alloced);
                }
                line[len++] = ch;
        } while (ch != '\n');

        if (len == 0)
                return -1;

        line[len] = '\0';
        *lineptr = line;
        *n = alloced;
        return len;
}
#endif

#ifndef HAVE_TTYNAME_R
int ttyname_r(int fd, char *buf, size_t buflen)
{
        int r;
        char path[sizeof("/proc/self/fd/%d") + sizeof(int)*3];

        if (!isatty(fd))
                return errno == EINVAL ? ENOTTY : errno;
        sprintf(path, "/proc/self/fd/%d", fd);
        r = readlink(path, buf, buflen);
        if (r < 0)
                return errno;
        if (r >= buflen)
                return ERANGE;
        buf[r] = '\0';
        return 0;
}
#endif