Путь: Toys/POSIX, команды версии: Ver.4 Ver.9 split Комментарии в файле split.c :
Исходный текст в файле split.c #define FOR_split #include "toys.h" GLOBALS( long n, l, b, a; char *outfile; ) static void do_split(int infd, char *in) { unsigned long bytesleft, linesleft, filenum, len, pos; int outfd = -1; struct stat st; // posix doesn't cover permissions on output file, so copy input (or 0777) st.st_mode = 0777; st.st_size = 0; fstat(infd, &st); if (TT.n && (TT.b = st.st_size/TT.n)<1) return error_msg("%s: no size", in); len = pos = filenum = bytesleft = linesleft = 0; for (;;) { int i, j; // Refill toybuf? if (len == pos) { if (!(len = xread(infd, toybuf, sizeof(toybuf)))) break; pos = 0; } // Start new output file? if ((TT.b && !bytesleft) || (TT.l && !linesleft)) { char *s = TT.outfile + strlen(TT.outfile); j = filenum++; for (i = 0; i<TT.a; i++) { *(--s) = 'a'+(j%26); j /= 26; } if (j) error_exit("bad suffix"); bytesleft = TT.b + ((filenum == TT.n) ? st.st_size%TT.n : 0); linesleft = TT.l; xclose(outfd); outfd = xcreate(TT.outfile, O_RDWR|O_CREAT|O_TRUNC, st.st_mode & 0777); } // Write next chunk of output. if (TT.l) { for (i = pos; i < len; ) { if (toybuf[i++] == '\n' && !--linesleft) break; if (!--bytesleft) break; } j = i - pos; } else { j = len - pos; if (j > bytesleft) j = bytesleft; bytesleft -= j; } xwrite(outfd, toybuf+pos, j); pos += j; } if (CFG_TOYBOX_FREE) { xclose(outfd); if (infd) close(infd); free(TT.outfile); } xexit(); } void split_main(void) { if (!TT.b && !TT.l && !TT.n) TT.l = 1000; // Allocate template for output filenames TT.outfile = xmprintf("%s%*c", (toys.optc == 2) ? toys.optargs[1] : "x", (int)TT.a, ' '); // We only ever use one input, but this handles '-' or no input for us. loopfiles(toys.optargs, do_split); } |