dan the shell

dansh.cpp

// for MSVC: cl -I.. /Tp dansh.cpp curl.lib readline.lib ..\Release\json.lib
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <io.h>
namespace json {
#include "json.h"
}
#define READLINE_STATIC
#include <readline/readline.h>
#include <readline/history.h>
#include <curl/curl.h>
#define API_URL "http://api.dan.co.jp/lleval.cgi?c=callback&s="

typedef struct {
	char* data;     // response data from server
	size_t size;    // response size of data
} MEMFILE;

MEMFILE*
memfopen() {
	MEMFILE* mf = (MEMFILE*) malloc(sizeof(MEMFILE));
	mf->data = NULL;
	mf->size = 0;
	return mf;
}

void
memfclose(MEMFILE* mf) {
	if (mf->data) free(mf->data);
	free(mf);
}

size_t
memfwrite(char* ptr, size_t size, size_t nmemb, void* stream) {
	MEMFILE* mf = (MEMFILE*) stream;
	int block = size * nmemb;
	if (!mf->data)
		mf->data = (char*) malloc(block);
	else
		mf->data = (char*) realloc(mf->data, mf->size + block);
	if (mf->data) {
		memcpy(mf->data + mf->size, ptr, block);
		mf->size += block;
	}
	return block;
}

char*
memfstrdup(MEMFILE* mf) {
	char* buf = (char*) malloc(mf->size + 1);
	memcpy(buf, mf->data, mf->size);
	buf[mf->size] = 0;
	return buf;
}

char*
url_encode_alloc(const char* str, int force_encode) {
	const char* hex = "0123456789abcdef";

	char* buf = NULL;
	unsigned char* pbuf = NULL;
	int len = 0;

	if (!str) return NULL;
	len = strlen(str)*3;
	buf = (char*) malloc(len+1);
	memset(buf, 0, len+1);
	pbuf = (unsigned char*)buf;
	while(*str) {
		unsigned char c = (unsigned char)*str;
		if (c == ' ')
			*pbuf++ = '+';
		else if (c & 0x80 || force_encode) {
			*pbuf++ = '%';
			*pbuf++ = hex[c >> 4];
			*pbuf++ = hex[c & 0x0f];
		} else
			*pbuf++ = c;
		str++;
	}
	return buf;
}

void do_dan(const char* line, const char* lang) {
	char* url;
	if (line != NULL) {
		char* source = url_encode_alloc(line, TRUE);
		url = (char*) malloc(strlen(API_URL) + strlen(source) + 10);
		strcpy(url, API_URL);
		strcat(url, source);
		if (lang) {
			strcat(url, "&l=");
			strcat(url, lang);
		}
	} else {
		url = strdup("http://api.dan.co.jp/lleval.cgi?q=1");
	}

	MEMFILE* mf = memfopen();
	CURL* curl = curl_easy_init();
	curl_easy_setopt(curl, CURLOPT_URL, url);
	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, memfwrite);
	curl_easy_setopt(curl, CURLOPT_WRITEDATA, mf);
	CURLcode res = curl_easy_perform(curl);
	free(url);
	if (res == CURLE_OK) {
		char* data = memfstrdup(mf);
		memfclose(mf);

		// remove callback function
		char* ptr;
		ptr = strrchr(data, ')');
		if (ptr) *ptr = 0;
		ptr = strchr(data, '(');
		if (ptr) *ptr++ = 0;
		else ptr = data;

		json::json_object *obj = json::json_tokener_parse(ptr);
		if (!is_error(obj)) {
			if (line == NULL) {
				char *key;
				struct json::json_object *val;
				struct json::lh_entry *entry;
				for(entry = json_object_get_object(obj)->head; (entry ? (key = (char*)entry->k, val = (struct json::json_object*)entry->v, entry) : 0); entry = entry->next) {
					printf("%s:%s\n", key, json::json_object_get_string(val));
				}
			} else {
				json::json_object *result = json::json_object_object_get(obj, "stdout");
				if (!is_error(result)) {
					printf("%s\n", json::json_object_get_string(result));
					json_object_put(result);
				}
			}
		}
		free(data);
	}
	curl_easy_cleanup(curl);
}

int main(int argc, char **argv)
{
	char* line = NULL;

	//json::mc_set_debug(1);
	if (argc == 2) {
		FILE* fp = fopen(argv[1], "rb");
		if (!fp) {
			perror("can't open file");
			exit(-1);
		}
		char buf[BUFSIZ];
		while (fgets(buf, sizeof(buf), fp)) {
			if (!line) {
				if (strncmp(buf, "#!", 2))
					line = strdup(buf);
			} else {
				line = (char*) realloc(line, strlen(line) + strlen(buf) + 1);
				strcat(line, buf);
			}
		}
		fclose(fp);
		do_dan(line, NULL);
		free(line);
	}
	if (!isatty(fileno(stdin))) {
		char buf[BUFSIZ];
		while (fgets(buf, sizeof(buf), stdin)) {
			if (!line) {
				if (strncmp(buf, "#!", 2))
					line = strdup(buf);
			} else {
				line = (char*) realloc(line, strlen(line) + strlen(buf) + 1);
				strcat(line, buf);
			}
		}
		do_dan(line, NULL);
		free(line);
	} else {
		int history_count = 0;
		while (line = readline("dan> ")) {
            add_history(line);
			if (++history_count > 200) {
				free(remove_history(0));
			}
			if (!strcmp(line, "#!?")) {
				do_dan(NULL, NULL);
			} else
			if (line[0] == '#' && line[1] == '!') {
				char* ptr = strchr(line, ' ');
				if (ptr) {
					*ptr++ = 0;
					do_dan(ptr, line + 2);
				}
			} else
				do_dan(line, "pl"); // default: perl
			free(line);
		}
	}
	return 0;
}