linux系统库函数之strcat、strncat
165 /**
166 * strcat - Append one %NUL-terminated string to another
167 * @dest: The string to be appended to
168 * @src: The string to append to it
169 */
170 #undef strcat
171 char *strcat(char *dest, const char *src)
172 {
173 char *tmp = dest;
174
175 while (*dest)
176 dest++;
177 while ((*dest++ = *src++) != '\0')
178 ;
179 return tmp;
180 }
181 EXPORT_SYMBOL(strcat);
182 #endif
用于将src所指向的字符串拷贝到dest所指向字符串末尾。
184 #ifndef __HAVE_ARCH_STRNCAT
185 /**
186 * strncat - Append a length-limited, %NUL-terminated string to another
187 * @dest: The string to be appended to
188 * @src: The string to append to it
189 * @count: The maximum numbers of bytes to copy
190 *
191 * Note that in contrast to strncpy(), strncat() ensures the result is
192 * terminated.
193 */
194 char *strncat(char *dest, const char *src, size_t count)
195 {
196 char *tmp = dest;
197
198 if (count) {
199 while (*dest)
200 dest++;
201 while ((*dest++ = *src++) != 0) {
202 if (--count == 0) {
203 *dest = '\0';
204 break;
205 }
206 }
207 }
208 return tmp;
209 }
210 EXPORT_SYMBOL(strncat);
211 #endif
同strcat函数不同的是，如果没有到字符串结尾，它只拷贝count大小字节数据，并且在dest末尾加上字符串的结束符'/0'
