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Diffstat (limited to 'docs/examples/getinmemory.c')
-rw-r--r-- | docs/examples/getinmemory.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/docs/examples/getinmemory.c b/docs/examples/getinmemory.c new file mode 100644 index 0000000..635a936 --- /dev/null +++ b/docs/examples/getinmemory.c @@ -0,0 +1,99 @@ +/***************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * + * Example source code to show how the callback function can be used to + * download data into a chunk of memory instead of storing it in a file. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include <curl/curl.h> + +struct MemoryStruct { + char *memory; + size_t size; +}; + + +static size_t +WriteMemoryCallback(void *ptr, size_t size, size_t nmemb, void *data) +{ + size_t realsize = size * nmemb; + struct MemoryStruct *mem = (struct MemoryStruct *)data; + + mem->memory = realloc(mem->memory, mem->size + realsize + 1); + if (mem->memory == NULL) { + /* out of memory! */ + printf("not enough memory (realloc returned NULL)\n"); + exit(EXIT_FAILURE); + } + + memcpy(&(mem->memory[mem->size]), ptr, realsize); + mem->size += realsize; + mem->memory[mem->size] = 0; + + return realsize; +} + + +int main(int argc, char **argv) +{ + CURL *curl_handle; + + struct MemoryStruct chunk; + + chunk.memory = malloc(1); /* will be grown as needed by the realloc above */ + chunk.size = 0; /* no data at this point */ + + curl_global_init(CURL_GLOBAL_ALL); + + /* init the curl session */ + curl_handle = curl_easy_init(); + + /* specify URL to get */ + curl_easy_setopt(curl_handle, CURLOPT_URL, "http://www.example.com/"); + + /* send all data to this function */ + curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, WriteMemoryCallback); + + /* we pass our 'chunk' struct to the callback function */ + curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, (void *)&chunk); + + /* some servers don't like requests that are made without a user-agent + field, so we provide one */ + curl_easy_setopt(curl_handle, CURLOPT_USERAGENT, "libcurl-agent/1.0"); + + /* get it! */ + curl_easy_perform(curl_handle); + + /* cleanup curl stuff */ + curl_easy_cleanup(curl_handle); + + /* + * Now, our chunk.memory points to a memory block that is chunk.size + * bytes big and contains the remote file. + * + * Do something nice with it! + * + * You should be aware of the fact that at this point we might have an + * allocated data block, and nothing has yet deallocated that data. So when + * you're done with it, you should free() it as a nice application. + */ + + printf("%lu bytes retrieved\n", chunk.size); + + if(chunk.memory) + free(chunk.memory); + + /* we're done with libcurl, so clean it up */ + curl_global_cleanup(); + + return 0; +} |