retroforth/literate/Unu.md
crc dc92b053d7 more move from ```` to ~~~ fencing
FossilOrigin-Name: 486430190417f9cf5f6239a9d5171822aec62c761df90dc03cb5c95558ec6973
2017-10-20 13:02:14 +00:00

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2.1 KiB
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# 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;
}
~~~