retroforth/literate/Unu.md
crc 183c5bae38 Initial checkin (from 58fa921 in the old git repo)
FossilOrigin-Name: d2b8467883db80cb179089e1db1b1ed4dff1f11b4bee7086ee46d83f3ee0136e
2017-10-16 16:09:39 +00:00

110 lines
2.1 KiB
Markdown

# Unu
unu
(verb) (-hia) pull out, withdraw, draw out, extract.
Unu is a tool for extracting fenced code blocks from Markdown documents.
I always found documenting my projects to be annoying. Eventually I decided to start mixing the code into the commentary using Markdown. Unu is the tool I use to extract the sources from the original files. I've found that this makes it easier for me to keep the commentary up to date.
## The Code
### Headers
````
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
````
I use this for readability purposes.
````
#define KiB * 1024
````
### read_line(FILE *file, char *line_buffer)
````
void read_line(FILE *file, char *line_buffer) {
if (file == NULL || line_buffer == NULL)
{
printf("Error: file or line buffer pointer is null.");
exit(1);
}
int ch = getc(file);
int count = 0;
while ((ch != '\n') && (ch != EOF)) {
line_buffer[count] = ch;
count++;
ch = getc(file);
}
line_buffer[count] = '\0';
}
````
### extract(char *fname)
The line buffer needs to be big enough for the longest lines in your source files. Here it's capped at 16KiB, which is sufficient for everything I've used Unu with so far.
````
char source[16 KiB];
````
````
int fenced(char *s)
{
int a = strcmp(s, "```");
int b = strcmp(s, "~~~");
if (a == 0) return 1;
if (b == 0) return 1;
return 0;
}
void extract(char *fname) {
char *buffer = (char *)source;
char fence[4];
FILE *fp;
int inBlock;
inBlock = 0;
fp = fopen(fname, "r");
if (fp == NULL)
return;
while (!feof(fp)) {
read_line(fp, buffer);
strncpy(fence, buffer, 3);
fence[3] = '\0';
if (fenced(fence)) {
if (inBlock == 0)
inBlock = 1;
else
inBlock = 0;
} else {
if ((inBlock == 1) && (strlen(buffer) != 0))
printf("%s\n", buffer);
}
}
fclose(fp);
}
````
### main(int argc, char **argv)
````
int main(int argc, char **argv) {
int i = 1;
if (argc > 1) {
while (i < argc) {
extract(argv[i++]);
}
}
else
printf("unu\n(c) 2013-2017 charles childers\n\nTry:\n %s filename\n", argv[0]);
return 0;
}
````