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/* unent -- expand HTML entities
*
* Author: Bert Bos
* Created: 10 Aug 2008
*/
#include "config.h"
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <ctype.h>
#include "export.h"
#include "unent.e"
static int leave_builtin = 0; /* Leave standard entities untouched */
static int fix_ampersands = 0; /* Replace lone and unrecognized & by & */
/* append_utf8 -- append the UTF-8 sequence for code n */
static void append_utf8(const int n)
{
if (n <= 0x7F) {
putchar(n);
} else if (n <= 0x7FF) {
putchar(0xC0 | (n >> 6));
putchar(0x80 | (n & 0x3F));
} else if (n <= 0xFFFF) {
putchar(0xE0 | (n >> 12));
putchar(0x80 | ((n >> 6) & 0x3F));
putchar(0x80 | (n & 0x3F));
} else if (n <= 0x1FFFFF) {
putchar(0xF0 | (n >> 18));
putchar(0x80 | ((n >> 12) & 0x3F));
putchar(0x80 | ((n >> 6) & 0x3F));
putchar(0x80 | (n & 0x3F));
} else if (n <= 0x3FFFFFF) {
putchar(0xF0 | (n >> 24));
putchar(0x80 | ((n >> 18) & 0x3F));
putchar(0x80 | ((n >> 12) & 0x3F));
putchar(0x80 | ((n >> 6) & 0x3F));
putchar(0x80 | (n & 0x3F));
} else {
putchar(0xF0 | (n >> 30));
putchar(0x80 | ((n >> 24) & 0x3F));
putchar(0x80 | ((n >> 18) & 0x3F));
putchar(0x80 | ((n >> 12) & 0x3F));
putchar(0x80 | ((n >> 6) & 0x3F));
putchar(0x80 | (n & 0x3F));
}
}
#define is_builtin(c) ((c)=='&'||(c)=='\''||(c)=='"'||(c)=='<'||(c)=='>')
#define hexval(c) ((c) <= '9' ? (c)-'0' : (c) <= 'F' ? 10+(c)-'A' : 10+(c)-'a')
/* expand -- print string, expanding entities to UTF-8 sequences */
static void expand(FILE *infile)
{
const struct _Entity *e;
int n, c;
char s[12]; /* Longest entity name has 8 characters */
while ((c = fgetc(infile)) != EOF) {
if (c != '&') { /* Literal character */
putchar(c);
} else if ((c = fgetc(infile)), isalnum(c)) { /* Named entity, e.g., < */
s[0] = c;
n = 1;
while ((c = fgetc(infile)), isalnum(c) && n < sizeof(s) - 1) s[n++] = c;
s[n] = '\0';
if (! (e = lookup_entity(s, n))) { /* Unknown entity */
if (fix_ampersands) fputs("&", stdout); else putchar('&');
fputs(s, stdout);
ungetc(c, infile);
} else {
if (leave_builtin && is_builtin(e->code)) printf("&%s;", s);
else append_utf8(e->code);
if (c != ';') ungetc(c, infile);
}
} else if (c == '#') { /* Numeric entity */
if ((c = fgetc(infile)), isdigit(c)) { /* Decimal entity, e.g., */
n = c - '0';
while ((c = fgetc(infile)), isdigit(c)) n = 10 * n + c - '0';
if (leave_builtin && is_builtin(n)) printf("&#%d;", n);
else append_utf8(n);
if (c != ';') ungetc(c, infile);
} else if (c == 'x') { /* Hexadecimal entity, e.g., 
 */
if ((c = fgetc(infile)), isxdigit(c)) {
n = hexval(c);
while ((c = fgetc(infile)), isxdigit(c)) n = 16 * n + hexval(c);
if (leave_builtin && is_builtin(n)) printf("&#x%x;", n);
else append_utf8(n);
if (c != ';') ungetc(c, infile);
} else { /* Invalid hexadecimal entity syntax */
if (fix_ampersands) fputs("&", stdout); else putchar('&');
printf("#x");
ungetc(c, infile);
}
} else { /* Invalid numerical entity */
if (fix_ampersands) fputs("&", stdout); else putchar('&');
putchar('#');
ungetc(c, infile);
}
} else { /* Neither a letter nor a '#' */
if (fix_ampersands) fputs("&", stdout); else putchar('&');
ungetc(c, infile);
}
}
/* SGML says also that a record-end (i.e., an end-of-line) may be
* used instead of a semicolon to end an entity reference. But the
* record-end is not suppressed in HTML and such an entity reference
* is invalid in XML, so we don't implement that rule here. Instead,
* the end-of-line is treated as any other character (other than
* semicolon) and left in the document.
*/
}
static void usage(const char *prog)
#if __GNUC__ > 2 || __GNUC__ == 2 && __GNUC_MINOR__ >= 5
__attribute__((__noreturn__))
#endif
;
/* usage -- print usage message and exit */
static void usage(const char *prog)
{
fprintf(stderr, "Version %s\nUsage: %s [-b] [-f] [file]\n", VERSION, prog);
exit(2);
}
/* main -- read input, expand entities, write out again */
int main(int argc, char *argv[])
{
FILE *infile;
int c;
while ((c = getopt(argc, argv, "bf")) != -1)
switch (c) {
case 'b': leave_builtin = 1; break;
case 'f': fix_ampersands = 1; break;
default: usage(argv[0]);
}
if (optind == argc) infile = stdin;
else if (optind == argc - 1) infile = fopen(argv[optind], "r");
else usage(argv[0]);
if (infile == NULL) {perror(argv[optind]); exit(1);}
expand(infile);
fclose(infile);
return 0;
}
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