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C

/** Copyright 2008, 2012 Neil Edelman, distributed under the terms of the
GNU General Public License, see copying.txt
Parsing of strings. '~' on a line by itself is recognised in ".newsfile.rss"
and ".sitemap.xml" as a <head>~<body>~<tail>; there should be two of them.
Parsed in ".index.html",
* @(content) prints {content.d}, or, if it is missing, {index.d};
* @(files)\{} repeats for all the files in the directory the contents of the
argument;
* @(htmlcontent);
* @(pwd)\{} prints the directory, the argument is the separator;
eg, @(pwd)\{/};
* @(root)\{}, like @(pwd), except up instead of down;
* @(now) prints the date and the time in UTC.
Further parsed in @(files){} in ".index.html",
* @(filealt) prints Dir or File;
* @(filedesc);
* @(filehref) prints the filename or the {.link};
* @(fileicon) prints it's {.d.jpeg}, or if it is not there, {dir.jpeg} or
{file.jpeg};
* @(filename) prints the file name;
* @(filesize) prints the file size, if it exits;
* @(now) prints the date and the time in UTC.
Parsed in ".newsfeed.rss",
* @(date) prints the date on the news file;
* @(news) prints the contents of the file (as a text file);
* @(newsname) prints the filename of the news story;
* @(now) prints the date and the time in UTC;
* @(title) prints the second line in the {.news}.
@title Parser
@author Neil
@std C89/90
@version 1.1; 2017-03 fixed pedantic warnings; command-line improvements
@since 0.6; 2008-03-21 */
#include <stdio.h> /* [f]printf FILE */
#include <stdlib.h> /* malloc */
#include <string.h> /* strstr, strpbrk */
#include "Widget.h"
#include "Parser.h"
/* private */
static const int maxRecursion = 16;
/* public */
struct Parser {
char *str;
char *pos;
char *rew;
int recursion;
};
/* private - this is the list of 'widgets', see Widget.c - add widgets to here
to make them recognised - ASCIIbetical */
static const struct Symbol {
const char *const symbol;
const ParserWidget handler;
const int onlyInRoot; /* fixme: not used, just trust the users? haha */
} sym[] = {
{ "content", &WidgetContent, 0 }, /* index */
{ "date", &WidgetDate, 0 }, /* news */
{ "filealt", &WidgetFilealt, 0 }, /* files */
{ "filedesc", &WidgetFiledesc, 0 }, /* files */
{ "filehref", &WidgetFilehref, 0 }, /* files */
{ "fileicon", &WidgetFileicon, 0 }, /* files */
{ "filename", &WidgetFilename, 0 }, /* files */
{ "files", &WidgetFiles, -1 }, /* index */
{ "filesize", &WidgetFilesize, 0 }, /* files */
/*{ "folder", 0, -1 }, *//* replaced by ~ - scetchy */
{ "htmlcontent",&WidgetContent,0 }, /* index */
{ "news", &WidgetNews, 0 }, /* news */
{ "newsname", &WidgetNewsname, 0 }, /* news */
{ "now", &WidgetNow, 0 }, /* any */
{ "pwd", &WidgetPwd, -1 }, /* index */
{ "root", &WidgetRoot, -1 }, /* like pwd except up instead of dn */
{ "title", &WidgetTitle, 0 } /* news */
};
/* private */
static const struct Symbol *match(const char *str, const char *end);
/** @return Creates a parser for the string, {str}. */
struct Parser *Parser(char *const str) {
struct Parser *p;
if(!(p = malloc(sizeof *p))) return 0;
p->str = str;
p->pos = p->str;
p->rew = p->str;
p->recursion = 0;
return p;
}
/** @param p_ptr: A pointer to the {Parser} that's to be destucted. */
void Parser_(struct Parser **const p_ptr) {
struct Parser *p;
if(!p_ptr || !(p = *p_ptr)) return;
if(p->recursion) fprintf(stderr, "Parser~: a file was closed with recursion level of %d; syntax error?\n", p->recursion);
free(p);
*p_ptr = 0;
}
/** Resets the parser, {p}. */
void ParserRewind(struct Parser *p) {
if(!p) return;
p->pos = p->rew;
}
/** Parse, called recursively.
@param f: Called in the handler to {ParserWidget}s.
@param invisible: No output.
@param fp: Output.
@fixme This fn needs rewriting; messy.
@fixme Invisible, hack. */
int ParserParse(struct Parser *p, struct Files *const f, int invisible,
FILE *fp) {
char *mark;
if(!p || !fp || !p->pos) return 0;
if(++p->recursion > maxRecursion) fprintf(stderr, "Parser::parse: %d "
"recursion levels reached (Ctrl-C to stop!)\n", p->recursion);
mark = p->pos;
if(p->recursion == 1) p->rew = mark;
for( ; ; ) {
p->pos = strpbrk(p->pos, "@}~");
if(!p->pos) {
if(!invisible) fprintf(fp, "%.*s", (int)(p->pos - mark), mark);
break;
} else if(*p->pos == '}') {
if(!invisible) fprintf(fp, "%.*s", (int)(p->pos - mark), mark);
p->pos++;
break;
} else if(*p->pos == '~') {
/* a tilde on a line by itself */
if(p->recursion == 1 &&
((p->pos <= p->str || *(p->pos - 1) == '\n') &&
*(p->pos + 1) == '\n')) {
if(!invisible) fprintf(fp, "%.*s", (int)(p->pos - mark), mark);
p->pos += 2; /* "~\n" */
p->recursion = 0;
return -1;
}
p->pos++;
} else if(*(p->pos + 1) == '(') { /* the only one left is @ */
const struct Symbol *m;
int over = 0, open;
char *start = p->pos + 2, *end;
if(!invisible) fprintf(fp, "%.*s", (int)(p->pos - mark), mark);
if(!(end = strpbrk(start, ")"))) break; /* syntax error */
if(!(m = match(start, end))) fprintf(stderr, "Parser::parse: "
"symbol not reconised, '%.*s.'\n", (int)(end - start), start);
/* if(p->recursion == 1 && m && m->onlyInRoot) return -1; ? */
open = *(end + 1) == '{' ? -1 : 0;
do {
/* -> widget.c */
if(m && m->handler && !invisible) over = m->handler(f, fp);
p->pos = end + (open ? 2 : 1);
/* recurse between {} */
if(open) ParserParse(p, f, invisible || !over, fp);
} while(over);
mark = p->pos;
} else { /* @ by itself */
p->pos++;
}
}
p->recursion--;
return 0;
}
/** binary search */
static const struct Symbol *match(const char *str, const char *end) {
const int N = sizeof(sym) / sizeof(struct Symbol);
int a, lo = 0, mid, hi = N - 1;
size_t lenMatch, lenComp;
lenMatch = end - str;
while(lo <= hi) {
mid = (lo + hi) >> 1;
/* this is highly inefficient */
lenComp = strlen(sym[mid].symbol);
a = strncmp(str, sym[mid].symbol,
lenMatch > lenComp ? lenMatch : lenComp);
if (a < 0) hi = mid - 1;
else if(a > 0) lo = mid + 1;
else return &sym[mid];
}
return 0;
}