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#include <stdio.h>
#include "buf.h"
#include <string.h>
#include <stdlib.h>
typedef enum {
false,
true
} bool;
FILE* getfile(int argc, char** argv){
if (argc >= 2)
return fopen(argv[1], "r");
else
return stdin;
}
// file read & buffer fill helpers
FILE* in;
buf* inbuf;
size_t fillbuf(size_t len){ // returns real len
int c;
size_t set;
for (set = buflen(inbuf); set < len && (c = fgetc(in)) != EOF;set++)
inschrbuf(inbuf, c);
return set;
}
size_t chrfill(char chr){
size_t line;
size_t len = buflen(inbuf);
char* str = peekstrbuf(inbuf, 0, len);
for (line = 0; line < len; line++)
if (str[line] == chr) return line+1;
for (int c = 0; c != chr && (c = fgetc(in)) != EOF; line++)
inschrbuf(inbuf, c);
return line;
}
// typesetting config and commands to change.
int width = 80;
bool brk = false; // not implemented
char* center(char* txt){
size_t len = strlen(txt);
int max = width/2 + len/2; // excluding terminator
int min = max-len+1; // first index of *txt
char* str = malloc(sizeof(char)*(max + 1));
str[max] = 0;
for (int i=0; i < min; i++) str[i] = ' ';
memcpy(str+min, txt, len);
return str;
}
char* setwidth(char* txt){
sscanf(txt, "%d", &width);
return NULL;
}
char* cmds[] = {"CT ", "W "};
char* (*call[])(char* txt) = {center, setwidth};
char* cmd(void){
char* dat = popstrbuf(inbuf, chrfill('\n'));
size_t low = 0; size_t high = sizeof(cmds)/sizeof(*cmds); //len
while (high >= low){
int mid = ((unsigned int)low + (unsigned int)high) >> 1;
char* mval = cmds[mid];
int cmp = strncmp(dat, mval, strlen(mval));
if (cmp < 0) // dat < mval
high = mid - 1;
else if (cmp > 0)
low = mid + 1;
else return call[mid](dat+strlen(mval));
}
return NULL;
}
// normal typesetting
char* typeset(void){
return popstrbuf(inbuf, chrfill('\n'));
}
// a parser to choose when to typeset and when to run a command
char* line(void){
size_t sz;
if ( (sz = fillbuf(2)) == 0)
return "";
char* twobytes = peekstrbuf(inbuf, 0, 2); // .., .\n, or ^.?
if (sz == 1 || twobytes[1] == '\n') return typeset();
if (twobytes[0] == '.') popchrbuf(inbuf);
if (twobytes[0] == '.' && twobytes[1] != '.'){
char* data = cmd();
if (data) return data;
return line();
} else {
return typeset();
}
}
// orchestration
int main(int argc, char** argv){
int c;
in = getfile(argc, argv);
inbuf = newbuf(256);
if (in == NULL){
perror(argv[1]);
return 1;
}
char* out;
while ( (out = line())[0] != '\0'){
printf("%s",out);
}
fclose(in);
return 0;
}
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