Путь: Toys/POSIX, команды версии: Ver.4 Ver.9 wc Комментарии в файле wc.c :
Исходный текст в файле wc.c #define FOR_wc #include "toys.h" GLOBALS( unsigned long totals[4]; ) static void show_lengths(unsigned long *lengths, char *name) { int i, space = 0, first = 1; // POSIX says there should never be leading spaces, but accepts that // traditional implementations use 7 spaces, unless only one file (or // just stdin) is being counted, when there should be no leading spaces, // *except* for the case where we're going to output multiple numbers. // And, yes, folks have test scripts that rely on all this nonsense :-( // Note: sufficiently modern versions of coreutils wc will use the smallest // column width necessary to have all columns be equal width rather than 0. if (!(!toys.optc && !(toys.optflags & (toys.optflags-1))) && toys.optc!=1) space = 7; for (i = 0; i<4; i++) { if (toys.optflags&(1<<i)) { printf(" %*ld"+first, space, lengths[i]); first = 0; } TT.totals[i] += lengths[i]; } if (*toys.optargs) printf(" %s", name); xputc('\n'); } static void do_wc(int fd, char *name) { int len = 0, clen = 1, space = 0; unsigned long word = 0, lengths[] = {0,0,0,0}; // Speed up common case: wc -c normalfile is file length. if (toys.optflags == FLAG_c) { struct stat st; // On Linux, files in /proc often report their size as 0. if (!fstat(fd, &st) && S_ISREG(st.st_mode) && st.st_size) { lengths[2] = st.st_size; goto show; } } for (;;) { int pos, done = 0, len2 = read(fd, toybuf+len, sizeof(toybuf)-len); unsigned wchar; if (len2<0) perror_msg_raw(name); else len += len2; if (len2<1) done++; for (pos = 0; pos<len; pos++) { if (toybuf[pos]=='\n') lengths[0]++; lengths[2]++; if (FLAG(m)) { // If we've consumed next wide char if (--clen<1) { // next wide size, don't count invalid, fetch more data if necessary clen = utf8towc(&wchar, toybuf+pos, len-pos); if (clen == -1) continue; if (clen == -2 && !done) break; lengths[3]++; space = iswspace(wchar); } } else space = isspace(toybuf[pos]); if (space) word=0; else { if (!word) lengths[1]++; word=1; } } if (done) break; if (pos != len) memmove(toybuf, toybuf+pos, len-pos); len -= pos; } show: show_lengths(lengths, name); } void wc_main(void) { if (!toys.optflags) toys.optflags = FLAG_l|FLAG_w|FLAG_c; loopfiles(toys.optargs, do_wc); if (toys.optc>1) show_lengths(TT.totals, "total"); } |