CURLOPT_DEBUGFUNCTION(3)

1CURLOPT_DEBUGFUNCTION(3)   curl_easy_setopt options   CURLOPT_DEBUGFUNCTION(3)
2
3
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NAME

6       CURLOPT_DEBUGFUNCTION - debug callback
7

SYNOPSIS

9       #include <curl/curl.h>
10
11       typedef enum {
12         CURLINFO_TEXT = 0,
13         CURLINFO_HEADER_IN,    /* 1 */
14         CURLINFO_HEADER_OUT,   /* 2 */
15         CURLINFO_DATA_IN,      /* 3 */
16         CURLINFO_DATA_OUT,     /* 4 */
17         CURLINFO_SSL_DATA_IN,  /* 5 */
18         CURLINFO_SSL_DATA_OUT, /* 6 */
19         CURLINFO_END
20       } curl_infotype;
21
22       int debug_callback(CURL *handle,
23                          curl_infotype type,
24                          char *data,
25                          size_t size,
26                          void *userptr);
27
28       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DEBUGFUNCTION,
29                                 debug_callback);
30

DESCRIPTION

32       Pass a pointer to your callback function, which should match the proto‐
33       type shown above.
34
35       CURLOPT_DEBUGFUNCTION(3) replaces the standard debug function used when
36       CURLOPT_VERBOSE(3)  is in effect. This callback receives debug informa‐
37       tion, as specified in the type argument. This function must  return  0.
38       The  data  pointed to by the char * passed to this function WILL NOT be
39       zero terminated, but will be exactly of the size as told  by  the  size
40       argument.
41
42       The userptr argument is the pointer set with CURLOPT_DEBUGDATA(3).
43
44       Available curl_infotype values:
45
46       CURLINFO_TEXT
47              The data is informational text.
48
49       CURLINFO_HEADER_IN
50              The data is header (or header-like) data received from the peer.
51
52       CURLINFO_HEADER_OUT
53              The data is header (or header-like) data sent to the peer.
54
55       CURLINFO_DATA_IN
56              The data is protocol data received from the peer.
57
58       CURLINFO_DATA_OUT
59              The data is protocol data sent to the peer.
60
61       CURLINFO_SSL_DATA_OUT
62              The data is SSL/TLS (binary) data sent to the peer.
63
64       CURLINFO_SSL_DATA_IN
65              The data is SSL/TLS (binary) data received from the peer.
66

DEFAULT

68       NULL
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PROTOCOLS

71       All
72

EXAMPLE

74       static
75       void dump(const char *text,
76                 FILE *stream, unsigned char *ptr, size_t size)
77       {
78         size_t i;
79         size_t c;
80         unsigned int width=0x10;
81
82         fprintf(stream, "%s, %10.10ld bytes (0x%8.8lx)\n",
83                 text, (long)size, (long)size);
84
85         for(i=0; i<size; i+= width) {
86           fprintf(stream, "%4.4lx: ", (long)i);
87
88           /* show hex to the left */
89           for(c = 0; c < width; c++) {
90             if(i+c < size)
91               fprintf(stream, "%02x ", ptr[i+c]);
92             else
93               fputs("   ", stream);
94           }
95
96           /* show data on the right */
97           for(c = 0; (c < width) && (i+c < size); c++) {
98             char x = (ptr[i+c] >= 0x20 && ptr[i+c] < 0x80) ? ptr[i+c] : '.';
99             fputc(x, stream);
100           }
101
102           fputc('\n', stream); /* newline */
103         }
104       }
105
106       static
107       int my_trace(CURL *handle, curl_infotype type,
108                    char *data, size_t size,
109                    void *userp)
110       {
111         const char *text;
112         (void)handle; /* prevent compiler warning */
113         (void)userp;
114
115         switch (type) {
116         case CURLINFO_TEXT:
117           fprintf(stderr, "== Info: %s", data);
118         default: /* in case a new one is introduced to shock us */
119           return 0;
120
121         case CURLINFO_HEADER_OUT:
122           text = "=> Send header";
123           break;
124         case CURLINFO_DATA_OUT:
125           text = "=> Send data";
126           break;
127         case CURLINFO_SSL_DATA_OUT:
128           text = "=> Send SSL data";
129           break;
130         case CURLINFO_HEADER_IN:
131           text = "<= Recv header";
132           break;
133         case CURLINFO_DATA_IN:
134           text = "<= Recv data";
135           break;
136         case CURLINFO_SSL_DATA_IN:
137           text = "<= Recv SSL data";
138           break;
139         }
140
141         dump(text, stderr, (unsigned char *)data, size);
142         return 0;
143       }
144
145       int main(void)
146       {
147         CURL *curl;
148         CURLcode res;
149
150         curl = curl_easy_init();
151         if(curl) {
152           curl_easy_setopt(curl, CURLOPT_DEBUGFUNCTION, my_trace);
153
154           /* the DEBUGFUNCTION has no effect until we enable VERBOSE */
155           curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
156
157           /* example.com is redirected, so we tell libcurl to follow redirection */
158           curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
159
160           curl_easy_setopt(curl, CURLOPT_URL, "http://example.com/");
161           res = curl_easy_perform(curl);
162           /* Check for errors */
163           if(res != CURLE_OK)
164             fprintf(stderr, "curl_easy_perform() failed: %s\n",
165                     curl_easy_strerror(res));
166
167           /* always cleanup */
168           curl_easy_cleanup(curl);
169         }
170         return 0;
171       }
172

AVAILABILITY

174       Always
175

RETURN VALUE

177       Returns CURLE_OK
178