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#define _XOPEN_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include "viewhtml.h"
typedef enum {
Inline, Block, TableRow,
} ElementType;
typedef struct {
char *control_sequence;
} Style;
typedef struct {
char *name;
ElementType type;
const Style *style;
} TagInfo;
static const Style NullStyle = { "" };
static const Style BrightStyle = { "\033[1m" };
static const Style BlueStyle = { "\033[34m" };
static const Style RedStyle = { "\033[31m" };
#define NUM_TAGS 12
static const TagInfo tags[NUM_TAGS] = {
{ "p", Block, &NullStyle },
{ "h1", Block, &BrightStyle },
{ "h2", Block, &BrightStyle },
{ "h3", Block, &BrightStyle },
{ "h4", Block, &BrightStyle },
{ "h5", Block, &NullStyle },
{ "h6", Block, &NullStyle },
{ "b", Inline, &BrightStyle },
{ "i", Inline, &RedStyle },
{ "em", Inline, &RedStyle },
{ "a", Inline, &BlueStyle },
{ "tr", TableRow, &NullStyle },
};
typedef struct {
char *code;
char *text;
} EntityInfo;
#define NUM_ENTITIES 6
static const EntityInfo entities[NUM_ENTITIES] = {
{ "&", "&" },
{ "<", "<" },
{ ">", ">" },
{ """, "\"" },
{ " ", "\302\240" },
{ "–", "\342\200\223" },
};
static void reset_styles(FILE *file) {
fputs("\033[0m", file);
}
static void activate_style(FILE *file, const Style *style) {
fputs(style->control_sequence, file);
}
static void set_styles(FILE *file, int open_tags) {
reset_styles(file);
for (int t = 0; t < NUM_TAGS; t++) {
if (open_tags & (1 << t)) {
activate_style(file, tags[t].style);
}
}
}
static void handle_inline_element(FILE *file, int open_tags, bool *near_text) {
if (!*near_text) {
/* Spacing between block level elements and text */
fputs("\n\n", file);
set_styles(file, open_tags);
*near_text = true;
}
}
static void handle_tag(FILE *file, int *open_tags, bool *near_text, const char *tag, int taglen, bool open) {
/* Look up tag */
int t;
for (t = 0; t < NUM_TAGS; t++) {
if (!strncmp(tags[t].name, tag, taglen)) break;
}
if (t == NUM_TAGS) return;
/* Special care for some tags */
if (tags[t].type == Block) {
#if 0
if (*near_text && open) {
/* Start of block in a text */
fputs("\n\n", file); // TODO ignore trailing br tag
}
#endif
*near_text = false;
/* if (open) fputs("\n\n", file);
else *near_text = false;*/
} else if (tags[t].type == TableRow) {
/* A simple hack for tables */
fputs("\n", file);
}
/* The tag was found. Apply it */
if (open) *open_tags |= (1 << t);
else *open_tags &= ~(1 << t);
//fprintf(file, "<%s%*s>", open ? "" : "/", taglen, tag);
/* Handle some tags specially */
if (!strncmp(tag, "p", taglen)) {
fputs("\n\n", file);
} else if (!strncmp(tag, "br", taglen)) {
fputs("\n", file);
}
/* Update style */
set_styles(file, *open_tags);
}
static void print_html(FILE *file, const char *html) {
int open_tags = 0;
bool near_text = false;
const char *p = html;
while (*p != '\0') {
if (*p == '<') {
p++;
if (*p == '\0') break;
else if (*p == '/') {
/* Skip end tag */
const char *tagstart = ++p;
while ((*p != '>') && (*p != '\0')) p++;
handle_tag(file, &open_tags, &near_text, tagstart, p - tagstart, false);
} else {
/* Parse start tag */
const char *tagstart = p;
while ((*p != '>') && (*p != ' ') && (*p != '/') && (*p != '\0')) p++;
handle_tag(file, &open_tags, &near_text, tagstart, p - tagstart, true);
// FIXME Hack to display link URLs
if (*p == ' ') p++;
if (!strncmp("href=\"entry://", p, 14)) {
handle_inline_element(file, open_tags, &near_text);
const char *url = p+14;
fputs("[", file);
fwrite(url, 1, strcspn(url, "\""), file);
fputs("] ", file);
}
/* Skip to end of tag */
while ((*p != '>') && (*p != '\0')) p++;
}
/* Skip trailing > */
if (*p == '>') p++;
} else if (*p == '&') {
/* TODO parse entities */
for (int i = 0; i < NUM_ENTITIES; i++) {
const int len = strlen(entities[i].code);
if (!strncmp(entities[i].code, p, len)) {
p += len;
fputs(entities[i].text, file);
goto known_entity;
}
}
/* Print unknown entity as-is */
fputc('&', file);
p++;
known_entity: ;
//while ((*p != '>') && (*p != '\0')) p++;
} else if ((*p > 0) && (*p <= ' ')) {
/* Group spacing characters */
do p++; while ((*p > 0) && (*p <= ' '));
fputc(' ', file);
} else {
// TODO: Wrap words here instead of with "fmt", to avoid breaking control sequences
handle_inline_element(file, open_tags, &near_text);
fputc(*p, file);
p++;
}
}
}
void view_html(const char *html) {
/* FIXME fork and these variables in the forked process */
putenv("LESSHISTFILE=/dev/null");
//putenv("COLUMNS=100");
FILE *lesspipe = popen("fmt -w 100 | less -R -", "w");
//FILE *lesspipe = popen("fmt -w 100 -u | less -", "w");
//FILE *lesspipe = popen("pr -t -J -o 4 -w 100 | less -", "w");
print_html(lesspipe, html);
pclose(lesspipe);
}
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