docs.sheetjs.com/docz/static/mujs/SheetJSMu.c

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2024-04-22 19:38:55 +00:00
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "mujs.h"
/* -------------------- */
/* these helper functions are from the official repl example */
static void jsB_print(js_State *J) {
int i = 1, top = js_gettop(J);
for (; i < top; ++i) {
const char *s = js_tostring(J, i);
if (i > 1) putchar(' ');
/* note: the official example uses `fputs`, but `puts` makes more sense */
puts(s);
}
putchar('\n');
js_pushundefined(J);
}
static void report(js_State *J, const char *msg) { fprintf(stderr, "REPORT MSG: %s\n", msg); }
/* -------------------- */
/* base64 encoder */
const char Base64_map[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static int Base64_encode(char *dst, const char *src, int len) {
unsigned char c1 = 0, c2 = 0, c3 = 0;
char *p = dst;
size_t i = 0;
for(; i < len;) {
c1 = src[i++];
*p++ = Base64_map[(c1 >> 2)];
c2 = src[i++];
*p++ = Base64_map[((c1 & 3) << 4) | (c2 >> 4)];
c3 = src[i++];
*p++ = Base64_map[((c2 & 15) << 2) | (c3 >> 6)];
*p++ = Base64_map[c3 & 0x3F];
}
if(i < len) {
c1 = src[i++];
*p++ = Base64_map[(c1 >> 2)];
if(i == len) {
*p++ = Base64_map[(c1 & 3) << 4];
*p++ = '=';
} else {
c2 = src[i++];
*p++ = Base64_map[((c1 & 3) << 4) | (c2 >> 4)];
*p++ = Base64_map[(c2 & 15) << 2];
}
*p++ = '=';
}
*p++ = '\0';
return p - dst;
}
/* -------------------- */
/* read file from filesystem */
static char *read_file(const char *filename, size_t *sz) {
FILE *f = fopen(filename, "rb");
if(!f) return NULL;
long fsize; { fseek(f, 0, SEEK_END); fsize = ftell(f); fseek(f, 0, SEEK_SET); }
char *buf = (char *)malloc(fsize * sizeof(char));
*sz = fread((void *) buf, 1, fsize, f);
fclose(f);
return buf;
}
/* -------------------- */
int main(int argc, char **argv) {
/* initialize mujs */
js_State *J = js_newstate(NULL, NULL, 0);
js_setreport(J, report);
/* create `console.log` */
js_newcfunction(J, jsB_print, "print", 0);
js_setglobal(J, "print");
js_dostring(J, "var console = { log: print };");
/* create `global` variable */
js_dostring(J, "var global = (function() { return this; })(null);");
/* load scripts */
js_dofile(J, "shim.min.js");
js_dofile(J, "xlsx.full.min.js");
/* read file */
size_t dlen; char *dbuf = read_file(argv[1], &dlen);
/* base64 encode the file */
int sz = ((dlen + 2) / 3) * 4 + 1;
char *b64 = malloc(sz+1);
sz = Base64_encode(b64, dbuf, dlen);
/* create `buf` global from the data */
js_pushlstring(J, b64, sz);
js_setglobal(J, "buf");
/* parse file */
js_dostring(J, "var wb = XLSX.read(buf, {type: 'base64'});");
/* print CSV from first worksheet */
js_dostring(J, "var ws = wb.Sheets[wb.SheetNames[0]]");
js_dostring(J, "console.log(XLSX.utils.sheet_to_csv(ws));");
/* cleanup */
free(b64);
js_freestate(J);
return 0;
}