1 /*
2  * Replacements for common but usually nonstandard functions that aren't
3  * supplied by all platforms.
4  *
5  * Copyright (C) 2009 by Dan Fandrich <dan@coneharvesters.com>, et. al.
6  *
7  * Licensed under GPLv2, see file LICENSE in this source tree.
8  */
9 #include "libbb.h"
10 
11 #ifndef HAVE_STRCHRNUL
strchrnul(const char * s,int c)12 char* FAST_FUNC strchrnul(const char *s, int c)
13 {
14 	while (*s != '\0' && *s != c)
15 		s++;
16 	return (char*)s;
17 }
18 #endif
19 
20 #ifndef HAVE_USLEEP
usleep(unsigned usec)21 int FAST_FUNC usleep(unsigned usec)
22 {
23 	struct timespec ts;
24 	ts.tv_sec = usec / 1000000u;
25 	ts.tv_nsec = (usec % 1000000u) * 1000u;
26 	/*
27 	 * If a signal has non-default handler, nanosleep returns early.
28 	 * Our version of usleep doesn't return early
29 	 * if interrupted by such signals:
30 	 */
31 	while (nanosleep(&ts, &ts) != 0)
32 		continue;
33 	return 0;
34 }
35 #endif
36 
37 #ifndef HAVE_VASPRINTF
vasprintf(char ** string_ptr,const char * format,va_list p)38 int FAST_FUNC vasprintf(char **string_ptr, const char *format, va_list p)
39 {
40 	int r;
41 	va_list p2;
42 	char buf[128];
43 
44 	va_copy(p2, p);
45 	r = vsnprintf(buf, 128, format, p);
46 	va_end(p);
47 
48 	/* Note: can't use xstrdup/xmalloc, they call vasprintf (us) on failure! */
49 
50 	if (r < 128) {
51 		va_end(p2);
52 		*string_ptr = strdup(buf);
53 		return (*string_ptr ? r : -1);
54 	}
55 
56 	*string_ptr = malloc(r+1);
57 	r = (*string_ptr ? vsnprintf(*string_ptr, r+1, format, p2) : -1);
58 	va_end(p2);
59 
60 	return r;
61 }
62 #endif
63 
64 #ifndef HAVE_DPRINTF
65 /* dprintf is now part of POSIX.1, but was only added in 2008 */
dprintf(int fd,const char * format,...)66 int dprintf(int fd, const char *format, ...)
67 {
68 	va_list p;
69 	int r;
70 	char *string_ptr;
71 
72 	va_start(p, format);
73 	r = vasprintf(&string_ptr, format, p);
74 	va_end(p);
75 	if (r >= 0) {
76 		r = full_write(fd, string_ptr, r);
77 		free(string_ptr);
78 	}
79 	return r;
80 }
81 #endif
82 
83 #ifndef HAVE_MEMRCHR
84 /* Copyright (C) 2005 Free Software Foundation, Inc.
85  * memrchr() is a GNU function that might not be available everywhere.
86  * It's basically the inverse of memchr() - search backwards in a
87  * memory block for a particular character.
88  */
memrchr(const void * s,int c,size_t n)89 void* FAST_FUNC memrchr(const void *s, int c, size_t n)
90 {
91 	const char *start = s, *end = s;
92 
93 	end += n - 1;
94 
95 	while (end >= start) {
96 		if (*end == (char)c)
97 			return (void *) end;
98 		end--;
99 	}
100 
101 	return NULL;
102 }
103 #endif
104 
105 #ifndef HAVE_MKDTEMP
106 /* This is now actually part of POSIX.1, but was only added in 2008 */
mkdtemp(char * template)107 char* FAST_FUNC mkdtemp(char *template)
108 {
109 	/* NB: on error, mktemp returns an empty string, not NULL */
110 	if (mktemp(template)[0] == '\0' || mkdir(template, 0700) != 0)
111 		return NULL;
112 	return template;
113 }
114 #endif
115 
116 #ifndef HAVE_STRCASESTR
117 /* Copyright (c) 1999, 2000 The ht://Dig Group */
strcasestr(const char * s,const char * pattern)118 char* FAST_FUNC strcasestr(const char *s, const char *pattern)
119 {
120 	int length = strlen(pattern);
121 
122 	while (*s) {
123 		if (strncasecmp(s, pattern, length) == 0)
124 			return (char *)s;
125 		s++;
126 	}
127 	return 0;
128 }
129 #endif
130 
131 #ifndef HAVE_STRSEP
132 /* Copyright (C) 2004 Free Software Foundation, Inc. */
strsep(char ** stringp,const char * delim)133 char* FAST_FUNC strsep(char **stringp, const char *delim)
134 {
135 	char *start = *stringp;
136 	char *ptr;
137 
138 	if (!start)
139 		return NULL;
140 
141 	if (!*delim)
142 		ptr = start + strlen(start);
143 	else {
144 		ptr = strpbrk(start, delim);
145 		if (!ptr) {
146 			*stringp = NULL;
147 			return start;
148 		}
149 	}
150 
151 	*ptr = '\0';
152 	*stringp = ptr + 1;
153 
154 	return start;
155 }
156 #endif
157 
158 #ifndef HAVE_STPCPY
stpcpy(char * p,const char * to_add)159 char* FAST_FUNC stpcpy(char *p, const char *to_add)
160 {
161 	while ((*p = *to_add) != '\0') {
162 		p++;
163 		to_add++;
164 	}
165 	return p;
166 }
167 #endif
168 
169 #ifndef HAVE_STPNCPY
stpncpy(char * p,const char * to_add,size_t n)170 char* FAST_FUNC stpncpy(char *p, const char *to_add, size_t n)
171 {
172 	while (n != 0 && (*p = *to_add) != '\0') {
173 		p++;
174 		to_add++;
175 		n--;
176 	}
177 	return p;
178 }
179 #endif
180 
181 #ifndef HAVE_GETLINE
getline(char ** lineptr,size_t * n,FILE * stream)182 ssize_t FAST_FUNC getline(char **lineptr, size_t *n, FILE *stream)
183 {
184 	int ch;
185 	char *line = *lineptr;
186 	size_t alloced = *n;
187 	size_t len = 0;
188 
189 	do {
190 		ch = fgetc(stream);
191 		if (ch == EOF)
192 			break;
193 		if (len + 1 >= alloced) {
194 			alloced += alloced/4 + 64;
195 			line = xrealloc(line, alloced);
196 		}
197 		line[len++] = ch;
198 	} while (ch != '\n');
199 
200 	if (len == 0)
201 		return -1;
202 
203 	line[len] = '\0';
204 	*lineptr = line;
205 	*n = alloced;
206 	return len;
207 }
208 #endif
209 
210 #ifndef HAVE_TTYNAME_R
ttyname_r(int fd,char * buf,size_t buflen)211 int ttyname_r(int fd, char *buf, size_t buflen)
212 {
213 	int r;
214 	char path[sizeof("/proc/self/fd/%d") + sizeof(int)*3];
215 
216 	if (!isatty(fd))
217 		return errno == EINVAL ? ENOTTY : errno;
218 	sprintf(path, "/proc/self/fd/%d", fd);
219 	r = readlink(path, buf, buflen);
220 	if (r < 0)
221 		return errno;
222 	if (r >= buflen)
223 		return ERANGE;
224 	buf[r] = '\0';
225 	return 0;
226 }
227 #endif
228