C語言sscanf函數的總結

在處理字符串的程序當中，經常會分析字符串，從一大長串的字符串截取我們需要的數據，這如果通過自己手寫函數來分析，雖然可以，但當你知道sscanf的功能，那就自己寫函數分析就顯得多此一舉。

這些函數的使用都很簡單，總結一下，等下次使用一目了然。俗話說：好記性不如爛筆頭，記錄下來就是效率。

以下源代碼是本人測試的源文件，附帶講解注釋。

1. /*****************************************************
2. ** Name : sscanf.c
3. ** Author : gzshun
4. ** Version : 1.0
5. ** Date : 2011-12
6. ** Description : sscanf function
7. ******************************************************/
8. #include <stdio.h>
9. #include <stdlib.h>
10. #include <string.h>
12. static void sscanf_test(void);
14. static void sscanf_test(void)
15. {
16. int ret;
17. char *string;
18. int digit;
19. char buf1[255];
20. char buf2[255];
21. char buf3[255];
22. char buf4[255];
24. /*1.最簡單的用法*/
25. string = "china beijing 123";
26. ret = sscanf(string, "%s %s %d", buf1, buf2, &digit);
27. printf("1.string=%s\n", string);
28. printf("1.ret=%d, buf1=%s, buf2=%s, digit=%d\n\n", ret, buf1, buf2, digit);
29. /*
30. **執行結果:
31. **1.ret=2, buf1=china, buf2=beijing, digit=123
32. **可以看出,sscanf的返回值是讀取的參數個數
33. */
35. /*2.取指定長度的字符串*/
36. string = "123456789";
37. sscanf(string, "%5s", buf1);
38. printf("2.string=%s\n", string);
39. printf("2.buf1=%s\n\n", buf1);
40. /*
41. **執行結果:
42. **2.buf1=12345
43. */
45. /*3.取到指定字符為止的字符串*/
46. string = "123/456";
47. sscanf(string, "%[^/]", buf1);
48. printf("3.string=%s\n", string);
49. printf("3.buf1=%s\n\n", buf1);
50. /*
51. **執行結果:
52. **3.buf1=123
53. */
55. /*4.取到指定字符集為止的字符串*/
56. string = "123abcABC";
57. sscanf(string, "%[^A-Z]", buf1);
58. printf("4.string=%s\n", string);
59. printf("4.buf1=%s\n\n", buf1);
60. /*
61. **執行結果:
62. **4.buf1=123abc
63. */
65. /*5.取僅包含指定字符集的字符串*/
66. string = "0123abcABC";
67. sscanf(string, "%[0-9]%[a-z]%[A-Z]", buf1, buf2, buf3);
68. printf("5.string=%s\n", string);
69. printf("5.buf1=%s, buf2=%s, buf3=%s\n\n", buf1, buf2, buf3);
70. /*
71. **執行結果:
72. **5.buf1=123
73. */
75. /*6.獲取指定字符中間的字符串*/
76. string = "ios<Android>wp7";
77. sscanf(string, "%*[^<]<%[^>]", buf1);
78. printf("6.string=%s\n", string);
79. printf("6.buf1=%s\n\n", buf1);
80. /*
81. **執行結果:
82. **6.buf1=android
83. */
85. /*7.指定要跳過的字符串*/
86. string = "iosVSandroid";
87. sscanf(string, "%[a-z]VS%[a-z]", buf1, buf2);
88. printf("7.string=%s\n", string);
89. printf("7.buf1=%s, buf2=%s\n\n", buf1, buf2);
90. /*
91. **執行結果:
92. **7.buf1=ios, buf2=android
93. */
95. /*8.分割以某字符隔開的字符串*/
96. string = "android-iphone-wp7";
97. /*
98. **字符串取道'-'為止,後面還需要跟著分隔符'-',
99. **起到過濾作用,有點類似於第7點
100. */
101. sscanf(string, "%[^-]-%[^-]-%[^-]", buf1, buf2, buf3);
102. printf("8.string=%s\n", string);
103. printf("8.buf1=%s, buf2=%s, buf3=%s\n\n", buf1, buf2, buf3);
104. /*
105. **執行結果:
106. **8.buf1=android, buf2=iphone, buf3=wp7
107. */
109. /*9.提取郵箱地址*/
110. string = "Email:[email protected]";
111. sscanf(string, "%[^:]:%[^@]@%[^.].%s", buf1, buf2, buf3, buf4);
112. printf("9.string=%s\n", string);
113. printf("9.buf1=%s, buf2=%s, buf3=%s, buf4=%s\n\n", buf1, buf2, buf3, buf4);
114. /*
115. **執行結果:
116. **9.buf1=Email, buf2=beijing, buf3=sina, buf4=com.cn
117. */
118. }
120. int main(int argc, char **argv)
121. {
122. sscanf_test();
124. return 0;
125. }
127. /*
128. **測試程序
129. **環境:
130. **Linux Ubuntu 2.6.32-24-generic-pae #39-Ubuntu SMP Wed Jul 28 07:39:26 UTC 2010 i686 GNU/Linux
131. **gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5)
132. **
133. gzshun@ubuntu:~/c/sscanf$ gcc sscanf.c -o sscanf
134. gzshun@ubuntu:~/c/sscanf$ ./sscanf
135. 1.string=china beijing 123
136. 1.ret=3, buf1=china, buf2=beijing, digit=123
138. 2.string=123456789
139. 2.buf1=12345
141. 3.string=123/456
142. 3.buf1=123
144. 4.string=123abcABC
145. 4.buf1=123abc
147. 5.string=0123abcABC
148. 5.buf1=0123, buf2=abc, buf3=ABC
150. 6.string=ios<android>wp7
151. 6.buf1=android
153. 7.string=iosVSandroid
154. 7.buf1=ios, buf2=android
156. 8.string=android-iphone-wp7
157. 8.buf1=android, buf2=iphone, buf3=wp7
159. 9.string=Email:[email protected]
160. 9.buf1=Email, buf2=beijing, buf3=sina, buf4=com.cn
161. */