ref: e8cf7530517534ccd9f5b0469191aa7c41581120
dir: /sys/src/cmd/uniq.c/
/* * Deal with duplicated lines in a file */ #include <u.h> #include <libc.h> #include <bio.h> #include <ctype.h> int fields = 0; int letters = 0; int linec = 0; char mode; int uniq; char *b1, *b2; Biobuf fin; Biobuf fout; int gline(char *buf); void pline(char *buf); int equal(char *b1, char *b2); char* skip(char *s); void main(int argc, char *argv[]) { int f; argv0 = argv[0]; b1 = malloc(Bsize); b2 = malloc(Bsize); f = 0; while(argc > 1) { if(*argv[1] == '-') { if(isdigit(argv[1][1])) fields = atoi(&argv[1][1]); else mode = argv[1][1]; argc--; argv++; continue; } if(*argv[1] == '+') { letters = atoi(&argv[1][1]); argc--; argv++; continue; } f = open(argv[1], 0); if(f < 0) sysfatal("cannot open %s", argv[1]); break; } if(argc > 2) sysfatal("unexpected argument %s", argv[2]); Binit(&fin, f, OREAD); Binit(&fout, 1, OWRITE); if(gline(b1)) exits(0); for(;;) { linec++; if(gline(b2)) { pline(b1); exits(0); } if(!equal(b1, b2)) { pline(b1); linec = 0; do { linec++; if(gline(b1)) { pline(b2); exits(0); } } while(equal(b2, b1)); pline(b2); linec = 0; } } } int gline(char *buf) { int len; char *p; p = Brdline(&fin, '\n'); if(p == 0) return 1; len = Blinelen(&fin); if(len > Bsize) sysfatal("line too long"); memmove(buf, p, len); buf[len-1] = 0; return 0; } void pline(char *buf) { switch(mode) { case 'u': if(uniq) { uniq = 0; return; } break; case 'd': if(uniq) break; return; case 'c': Bprint(&fout, "%4d ", linec); } uniq = 0; Bprint(&fout, "%s\n", buf); } int equal(char *b1, char *b2) { char c; if(fields || letters) { b1 = skip(b1); b2 = skip(b2); } for(;;) { c = *b1++; if(c != *b2++) { if(c == 0 && mode == 's') return 1; return 0; } if(c == 0) { uniq++; return 1; } } } char* skip(char *s) { int nf, nl; nf = nl = 0; while(nf++ < fields) { while(*s == ' ' || *s == '\t') s++; while(!(*s == ' ' || *s == '\t' || *s == 0) ) s++; } while(nl++ < letters && *s != 0) s++; return s; }