diff options
Diffstat (limited to 'markdown.c')
| -rw-r--r-- | markdown.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/markdown.c b/markdown.c new file mode 100644 index 0000000..e7fed5d --- /dev/null +++ b/markdown.c @@ -0,0 +1,207 @@ +/* +a little program to convert markdown to html, for READMEs +I was using markdown.pl but that has some annoying problems +This doesn't support all of markdown; I'll add more as I need it. +*/ + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> + +/* output text with *s for italics and stuff */ +static void output_md_text(FILE *out, int *flags, int line_number, const char *text) { + enum { + FLAG_I = 0x01, /* italics */ + FLAG_B = 0x02, + FLAG_CODE = 0x04 + }; + const char *p; + + for (p = text; *p; ++p) { + if ((*flags & FLAG_CODE) && *p != '`') { + putc(*p, out); + continue; + } + switch (*p) { + case '*': + if (p[1] == '*') { + /* bold */ + if (*flags & FLAG_B) { + fprintf(out, "</b>"); + *flags &= ~FLAG_B; + } else { + fprintf(out, "<b>"); + *flags |= FLAG_B; + } + ++p; + } else { + /* italics */ + if (*flags & FLAG_I) { + fprintf(out, "</i>"); + *flags &= ~FLAG_I; + } else { + fprintf(out, "<i>"); + *flags |= FLAG_I; + } + } + break; + case '`': + /* code */ + if (*flags & FLAG_CODE) { + fprintf(out, "</code>"); + *flags &= ~FLAG_CODE; + } else { + fprintf(out, "<code>"); + *flags |= FLAG_CODE; + } + break; + case '[': { + /* link */ + const char *label, *url, *label_end, *url_end; + int n_label, n_url; + + label = p+1; + label_end = strchr(label, ']'); + if (!label_end) { + fprintf(stderr, "line %d: Unterminated link.\n", line_number); + exit(-1); + } + if (label_end[1] != '(') { + fprintf(stderr, "line %d: Bad link syntax.\n", line_number); + exit(-1); + } + url = label_end + 2; + url_end = strchr(url, ')'); + if (!url_end) { + fprintf(stderr, "line %d: Unterminated URL.\n", line_number); + exit(-1); + } + + n_label = (int)(label_end - label); + n_url = (int)(url_end - url); + fprintf(out, "<a href=\"%.*s\" target=\"_blank\">%.*s</a>", + n_url, url, n_label, label); + p = url_end; + } break; + case '-': + if (p[1] == '-') { + /* em dash */ + fprintf(out, "—"); + ++p; + } else { + goto default_case; + } + break; + default: + default_case: + putc(*p, out); + break; + } + } +} + +int main(int argc, char **argv) { + FILE *in, *out; + char line[1024] = {0}; + char title[256] = {0}; + int flags = 0, txtflags = 0; + int line_number = 0; + enum { + FLAG_UL = 1 + }; + + if (argc < 2) { + fprintf(stderr, "Please provide an input file.\n"); + return -1; + } + + { + const char *in_filename = argv[1]; + char out_filename[256] = {0}; + char *dot; + strncpy(out_filename, argv[1], 200); + dot = strrchr(out_filename, '.'); + if (!dot || strcmp(dot, ".md") != 0) { + fprintf(stderr, "Input filename does not end in .md\n"); + return -1; + } + *dot = '\0'; + strcpy(title, out_filename); + strcpy(dot, ".html"); + + + in = fopen(in_filename, "rb"); + out = fopen(out_filename, "wb"); + } + + if (!in) { + perror("Couldn't open input file"); + return -1; + } + if (!out) { + perror("Couldn't open output file"); + return -1; + } + + fprintf(out, + "<!DOCTYPE html>\n" + "<html lang=\"en\">\n" + "<head>\n" + "<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">\n" + "<meta charset=\"utf-8\">\n" + "<style>\n" + "body { font-family: sans-serif; }\n" + "</style>\n" + "<title>%s</title>\n" + "</head>\n" + "<body>\n" + "<p>\n", title + ); + while (fgets(line, sizeof line, in)) { + ++line_number; + line[strcspn(line, "\r\n")] = '\0'; + + if (line[0] == '#') { + /* heading */ + int n = 1; + while (line[n] == '#') ++n; + fprintf(out, "</p><h%d>", n); + output_md_text(out, &txtflags, line_number, line + n); + fprintf(out, "</h%d><p>\n", n); + } else if (line[0] == '\0') { + if (flags & FLAG_UL) { + fprintf(out, "</li></ul>\n"); + flags &= ~FLAG_UL; + } + fprintf(out, "</p>\n<p>\n"); + } else if (strncmp(line, "- ", 2) == 0) { + /* bullet */ + if (flags & FLAG_UL) { + fprintf(out, "</li><li>"); + } else { + fprintf(out, "<ul><li>"); + flags |= FLAG_UL; + } + output_md_text(out, &txtflags, line_number, line + 2); + fprintf(out, "\n"); + } else if (strncmp(line, "```", 3) == 0) { + fprintf(out, "<pre><code>\n"); + + while (fgets(line, sizeof line, in)) { + ++line_number; + if (strncmp(line, "```", 3) == 0) + break; + fprintf(out, "%s", line); + } + + fprintf(out, "</code></pre>\n"); + } else { + output_md_text(out, &txtflags, line_number, line); + fprintf(out, "\n"); + } + + + + } + fprintf(out, "</p>\n</body>\n</html>\n"); +} |