change the external code block formatting option into an actual external code block formatter

generate.c

@@ -1663,21 +1663,75 @@ printtable(Paragraph *pp, MMIOT *f)
     return 1;
 }
 
+/* external formatter caller for code blocks
+ */
+static int
+code_callback(Line *t, char *lang, int fenced, Line **ret, MMIOT *f)
+{
+    if ( f->cb->e_codefmt ) {
+	/* external code block formatter;  copy the text into a buffer,
+	 * call the formatter to style it, then dump that styled text
+	 * directly to the queue
+	 */
+	char *text;
+	char *fmt;
+	int size, copy_p;
+	Line *p;
+
+	for (size=0, p = t; p && (fenced ? p->is_fenced : 1); p = p->next )
+	    size += 1+S(p->text);
+
+	text = malloc(1+size);
+
+	for ( copy_p = 0; t && (fenced ? t->is_fenced : 1); t = t->next ) {
+	    memcpy(text+copy_p, T(t->text), S(t->text));
+	    copy_p += S(t->text);
+	    text[copy_p++] = '\n';
+	}
+	text[copy_p] = 0;
+
+
+	fmt = (*(f->cb->e_codefmt))(text, copy_p, (lang && lang[0]) ? lang : 0);
+	free(text);
+
+	if ( fmt ) {
+	    Qwrite(fmt, strlen(fmt), f);
+	    if ( f->cb->e_free )
+		(*(f->cb->e_free))(fmt, f->cb->e_data);
+	    *ret = t;
+	    return 1;
+	}
+    }
+    /* either the external formatter failed or doesn't exist,
+     * so fall back to the traditional codeblock format
+     */
+    *ret = 0;
+    return 0;
+}
+
+
 
 static Line *
 printfenced(Line *t, MMIOT *f)
 {
+    Line *ret;
+
+
     Qstring("<pre><code", f);
     if ( t->fence_class )
 	Qprintf(f, " class=\"%s\"", t->fence_class);
     Qchar('>', f);
-    while ( (t = t->next) && t->is_fenced ) {
-	code(f, T(t->text), S(t->text));
-	Qchar('\n', f);
+
+    if ( !code_callback(t, t->fence_class, 1, &ret, f) ) {
+	while ( (t = t->next) && t->is_fenced ) {
+	    code(f, T(t->text), S(t->text));
+	    Qchar('\n', f);
+	}
+	ret = t;
     }
 
     Qstring("</code></pre>\n", f);
-    return t;
+    return ret;
 }
 
 
@@ -1713,6 +1767,7 @@ printblock(Paragraph *pp, MMIOT *f)
     } while (t && (t = t->next) );
     text(f);
     Qstring(End[align], f);
+
     return 1;
 }
 
@@ -1721,42 +1776,8 @@ static void
 printcode(Line *t, char *lang, MMIOT *f)
 {
     int blanks;
+    Line *ret;
 
-    if ( f->cb->e_codefmt ) {
-	/* external code block formatter;  copy the text into a buffer,
-	 * call the formatter to style it, then dump that styled text
-	 * directly to the queue
-	 */
-	char *text;
-	char *fmt;
-	int size, copy_p;
-	Line *p;
-
-	for (size=0, p = t; p; p = p->next )
-	    size += 1+S(p->text);
-
-	text = malloc(1+size);
-
-	for ( copy_p = 0; t ; t = t->next ) {
-	    memcpy(text+copy_p, T(t->text), S(t->text));
-	    copy_p += S(t->text);
-	    text[copy_p++] = '\n';
-	}
-	text[copy_p] = 0;
-
-	fmt = (*(f->cb->e_codefmt))(text, copy_p, (lang && lang[0]) ? lang : 0);
-	free(text);
-
-	if ( fmt ) {
-	    Qwrite(fmt, strlen(fmt), f);
-	    if ( f->cb->e_free )
-		(*(f->cb->e_free))(fmt, f->cb->e_data);
-	    return;
-	}
-	/* otherwise the external formatter failed and we need to 
-	 * fall back to the traditional codeblock format
-	 */
-    }
 
     Qstring("<pre><code", f);
     if (lang && lang[0]) {
@@ -1765,16 +1786,19 @@ printcode(Line *t, char *lang, MMIOT *f)
       Qstring("\"", f);
     }
     Qstring(">", f);
-    for ( blanks = 0; t ; t = t->next ) {
-	if ( S(t->text) > t->dle ) {
-	    while ( blanks ) {
+
+    if ( !code_callback(t, lang, 0, &ret, f) ) {
+	for ( blanks = 0; t ; t = t->next ) {
+	    if ( S(t->text) > t->dle ) {
+		while ( blanks ) {
+		    Qchar('\n', f);
+		    --blanks;
+		}
+		code(f, T(t->text), S(t->text));
 		Qchar('\n', f);
-		--blanks;
 	    }
-	    code(f, T(t->text), S(t->text));
-	    Qchar('\n', f);
+	    else blanks++;
 	}
-	else blanks++;
     }
     Qstring("</code></pre>", f);
 }

main.c

@@ -14,6 +14,7 @@
 #include <string.h>
 #include <stdarg.h>
 #include <ctype.h>
+#include <unistd.h>
 
 #include "config.h"
 #include "amalloc.h"
@@ -97,46 +98,67 @@ free_it(char *object, void *ctx)
 	free(object);
 }
 
+
+char *external_formatter = 0;
+
+
+#define RECEIVER 0
+#define SENDER 1
+
 char *
 external_codefmt(char *src, int len, char *lang)
 {
-    int extra = 0;
-    int i, x;
+    int child_status;
+    int size, bufsize, curr;
     char *res;
 
-    if ( lang == 0 )
-	lang = "generic_code";
+    pid_t child;
 
-    for ( i=0; i < len; i++) {
-	if ( src[i] == '&' )
-	    extra += 5;
-	else if ( src[i] == '<' || src[i] == '>' )
-	    extra += 4;
+    int tochild[2], toparent[2];
+
+    if ( pipe(tochild) != 0 || pipe(toparent) != 0 ) {
+	perror("external_codefmt (pipe)");
+	res = malloc(len+1);
+	strcpy(res, src);
+	return res;
     }
 
-    /* 80 characters for the format wrappers */
-    if ( (res = malloc(len+extra+80+strlen(lang))) ==0 )
-	/* out of memory?  drat! */
-	return 0;
+    if ( (child = fork()) > 0 ) {
 
-    sprintf(res, "<pre><code class=\"%s\">\n", lang);
-    x = strlen(res);
-    for ( i=0; i < len; i++ ) {
-	switch (src[i]) {
-	case '&':   strcpy(&src[x], "&amp;");
-		    x += 5 /*strlen(&amp;)*/ ;
-		    break;
-	case '<':   strcpy(&src[x], "&lt;");
-		    x += 4 /*strlen(&lt;)*/ ;
-		    break;
-	case '>':   strcpy(&src[x], "&gt;");
-		    x += 4 /*strlen(&gt;)*/ ;
-		    break;
-	default:    res[x++] = src[i];
-		    break;
+	close(tochild[RECEIVER]);
+	close(toparent[SENDER]);
+
+	bufsize = 1000;
+	res = malloc(1+bufsize);
+	curr = 0;
+
+	/* parent */
+	write(tochild[SENDER], src, len);
+	close(tochild[SENDER]);
+
+	while ( (size = read(toparent[RECEIVER], res+curr, 1000)) > 0 ) {
+	    curr += size;
+	    res = realloc(res, bufsize += 1000);
 	}
+	res[curr] = 0;
+	waitpid(child, &child_status, WNOHANG);
+
+	close(toparent[RECEIVER]);
+
+	return res;
     }
-    strcpy(&res[x], "</code></pre>\n");
+    else if ( child == 0 ) {
+	close(tochild[SENDER]);
+	close(toparent[RECEIVER]);
+	close(1); dup2(toparent[SENDER], 1);
+	close(0); dup2(tochild[RECEIVER], 0);
+	system(external_formatter);
+	close(0); close(tochild[RECEIVER]);
+	close(1); close(toparent[SENDER]);
+	exit(0);
+    }
+    res = malloc(len+1);
+    strcpy(res, src);
     return res;
 }
 
@@ -158,11 +180,12 @@ struct h_opt opts[] = {
     { 0, 0,        'C', "prefix",    "prefix for markdown extra footnotes" },
     { 0, 0,        'o', "file",      "write output to file" },
     { 0, "squash", 'x', 0,           "squash toc labels to be more like github" },
-    { 0, "codefmt",'X', 0,           "use an external code formatter" },
+    { 0, "codefmt",'X', "command",   "use an external code formatter" },
     { 0, "help",   '?', 0,           "print a detailed usage message" },
 };
 #define NROPTS (sizeof opts/sizeof opts[0])
 
+
 int
 main(int argc, char **argv)
 {
@@ -268,6 +291,8 @@ main(int argc, char **argv)
 		    break;
 	case 'X':   use_e_codefmt = 1;
 		    mkd_set_flag_num(flags, MKD_FENCEDCODE);
+		    external_formatter = hoptarg(&blob);
+		    fprintf(stderr, "selected external formatter (%s)\n", external_formatter);
 		    break;
 	case '?':   hoptdescribe(pgm, opts, NROPTS, "[file]", 1);
 		    return 0;
@@ -323,6 +348,7 @@ main(int argc, char **argv)
 	}
 	if ( squash )
 	    mkd_e_anchor(doc, (mkd_callback_t) anchor_format);
+
 	if ( use_e_codefmt )
 	    mkd_e_code_format(doc, (mkd_callback_t)external_codefmt);