ref: 0e516cbf488a9ec8edae3dc6efca2baa0c3d95bd
dir: /sys/src/cmd/col.c/
/* col - eliminate reverse line feeds */ #include <u.h> #include <libc.h> #include <ctype.h> #include <bio.h> enum { ESC = '\033', RLF = '\013', PL = 256, LINELN = 800, Tabstop = 8, /* must be power of 2 */ }; static int bflag, xflag, fflag; static int cp, lp; static int half; static int ll, llh, mustwr; static int pcp = 0; static char *page[PL]; static char *line; static char lbuff[LINELN]; static Biobuf bin, bout; void emit(char *s, int lineno); void incr(void), decr(void); void outc(Rune); static void usage(void) { fprint(2, "usage: %s [-bfx]\n", argv0); exits("usage"); } void main(int argc, char **argv) { int i, lno; long ch; Rune c; ARGBEGIN{ case 'b': bflag++; break; case 'f': fflag++; break; case 'x': xflag++; break; default: usage(); }ARGEND; for (ll=0; ll < PL; ll++) page[ll] = nil; cp = 0; ll = 0; mustwr = PL; line = lbuff; Binit(&bin, 0, OREAD); Binit(&bout, 1, OWRITE); while ((ch = Bgetrune(&bin)) != Beof) { c = ch; switch (c) { case '\n': incr(); incr(); cp = 0; break; case '\0': break; case ESC: c = Bgetrune(&bin); switch (c) { case '7': /* reverse full line feed */ decr(); decr(); break; case '8': /* reverse half line feed */ if (fflag) decr(); else if (--half < -1) { decr(); decr(); half += 2; } break; case '9': /* forward half line feed */ if (fflag) incr(); else if (++half > 0) { incr(); incr(); half -= 2; } break; } break; case RLF: decr(); decr(); break; case '\r': cp = 0; break; case '\t': cp = (cp + Tabstop) & -Tabstop; break; case '\b': if (cp > 0) cp--; break; case ' ': cp++; break; default: if (!isascii(c) || isprint(c)) { outc(c); cp++; } break; } } for (i=0; i < PL; i++) { lno = (mustwr+i) % PL; if (page[lno] != 0) emit(page[lno], mustwr+i-PL); } emit(" ", (llh + 1) & -2); exits(0); } void outc(Rune c) { if (lp > cp) { line = lbuff; lp = 0; } while (lp < cp) { switch (*line) { case '\0': *line = ' '; lp++; break; case '\b': lp--; break; default: lp++; break; } line++; } while (*line == '\b') line += 2; if (bflag || *line == '\0' || *line == ' ') cp += runetochar(line, &c) - 1; else { char c1, c2, c3; c1 = *++line; *line++ = '\b'; c2 = *line; *line++ = c; while (c1) { c3 = *line; *line++ = c1; c1 = c2; c2 = c3; } lp = 0; line = lbuff; } } void store(int lno) { lno %= PL; if (page[lno] != nil) free(page[lno]); page[lno] = malloc((unsigned)strlen(lbuff) + 2); if (page[lno] == nil) sysfatal("out of memory"); strcpy(page[lno], lbuff); } void fetch(int lno) { char *p; lno %= PL; p = lbuff; while (*p) *p++ = '\0'; line = lbuff; lp = 0; if (page[lno]) strcpy(line, page[lno]); } void emit(char *s, int lineno) { int ncp; char *p; static int cline = 0; if (*s) { while (cline < lineno - 1) { Bputc(&bout, '\n'); pcp = 0; cline += 2; } if (cline != lineno) { Bputc(&bout, ESC); Bputc(&bout, '9'); cline++; } if (pcp) Bputc(&bout, '\r'); pcp = 0; p = s; while (*p) { ncp = pcp; while (*p++ == ' ') if ((++ncp & 7) == 0 && !xflag) { pcp = ncp; Bputc(&bout, '\t'); } if (!*--p) break; while (pcp < ncp) { Bputc(&bout, ' '); pcp++; } Bputc(&bout, *p); if (*p++ == '\b') pcp--; else pcp++; } } } void incr(void) { int lno; store(ll++); if (ll > llh) llh = ll; lno = ll % PL; if (ll >= mustwr && page[lno]) { emit(page[lno], ll - PL); mustwr++; free(page[lno]); page[lno] = nil; } fetch(ll); } void decr(void) { if (ll > mustwr - PL) { store(ll--); fetch(ll); } }