Move slurp_file() into library as jv_load_file()

Needed as part of creating a libjq.

main.c

@@ -6,6 +6,7 @@
 #include <unistd.h>
 #include "compile.h"
 #include "jv.h"
+#include "jv_file.h"
 #include "jv_parse.h"
 #include "execute.h"
 #include "config.h"  /* Autoconf generated header file */
@@ -96,43 +97,6 @@ static void process(jv value, int flags) {
   jq_teardown(&jq);
 }
 
-jv slurp_file(const char* filename, int raw) {
-  FILE* file = fopen(filename, "r");
-  struct jv_parser parser;
-  jv data;
-  if (!file) {
-    return jv_invalid_with_msg(jv_string_fmt("Could not open %s: %s",
-                                             filename,
-                                             strerror(errno)));
-  }
-  if (raw) {
-    data = jv_string("");
-  } else {
-    data = jv_array();
-    jv_parser_init(&parser);
-  }
-  while (!feof(file) && !ferror(file)) {
-    char buf[4096];
-    size_t n = fread(buf, 1, sizeof(buf), file);
-    if (raw) {
-      data = jv_string_concat(data, jv_string_sized(buf, (int)n));
-    } else {
-      jv_parser_set_buf(&parser, buf, strlen(buf), !feof(file));
-      jv value;
-      while (jv_is_valid((value = jv_parser_next(&parser))))
-        data = jv_array_append(data, value);
-    }
-  }
-  int badread = ferror(file);
-  fclose(file);
-  if (badread) {
-    jv_free(data);
-    return jv_invalid_with_msg(jv_string_fmt("Error reading from %s",
-                                             filename));
-  }
-  return data;
-}
-
 FILE* current_input;
 const char** input_filenames;
 int ninput_files;
@@ -224,7 +188,7 @@ int main(int argc, char* argv[]) {
       }
       jv arg = jv_object();
       arg = jv_object_set(arg, jv_string("name"), jv_string(argv[i+1]));
-      jv data = slurp_file(argv[i+2], 0);
+      jv data = jv_load_file(argv[i+2], 0);
       if (!jv_is_valid(data)) {
         data = jv_invalid_get_msg(data);
         fprintf(stderr, "%s: Bad JSON in --argfile %s %s: %s\n", progname,
@@ -260,7 +224,7 @@ int main(int argc, char* argv[]) {
   }
   
   if (options & FROM_FILE) {
-    jv data = slurp_file(program, 1);
+    jv data = jv_load_file(program, 1);
     if (!jv_is_valid(data)) {
       data = jv_invalid_get_msg(data);
       fprintf(stderr, "%s: %s\n", progname, jv_string_value(data));