1/* split.c - split a file into smaller files 2 * 3 * Copyright 2013 Rob Landley <rob@landley.net> 4 * 5 * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/split.html 6 * 7 * Standard does not cover: 8 * - should splitting an empty file produce an empty outfile? (Went with "no".) 9 * - permissions on output file 10 11USE_SPLIT(NEWTOY(split, ">2a#<1=2>9b#<1l#<1n#<1[!bl][!bn][!ln]", TOYFLAG_USR|TOYFLAG_BIN)) 12 13config SPLIT 14 bool "split" 15 default y 16 help 17 usage: split [-a SUFFIX_LEN] [-b BYTES] [-l LINES] [-n PARTS] [INPUT [OUTPUT]] 18 19 Copy INPUT (or stdin) data to a series of OUTPUT (or "x") files with 20 alphabetically increasing suffix (aa, ab, ac... az, ba, bb...). 21 22 -a Suffix length (default 2) 23 -b BYTES/file (10, 10k, 10m, 10g...) 24 -l LINES/file (default 1000) 25 -n PARTS many equal length files 26*/ 27 28#define FOR_split 29#include "toys.h" 30 31GLOBALS( 32 long n, l, b, a; 33 34 char *outfile; 35) 36 37static void do_split(int infd, char *in) 38{ 39 unsigned long bytesleft, linesleft, filenum, len, pos; 40 int outfd = -1; 41 struct stat st; 42 43 // posix doesn't cover permissions on output file, so copy input (or 0777) 44 st.st_mode = 0777; 45 st.st_size = 0; 46 fstat(infd, &st); 47 48 if (TT.n && (TT.b = st.st_size/TT.n)<1) return error_msg("%s: no size", in); 49 len = pos = filenum = bytesleft = linesleft = 0; 50 for (;;) { 51 int i, j; 52 53 // Refill toybuf? 54 if (len == pos) { 55 if (!(len = xread(infd, toybuf, sizeof(toybuf)))) break; 56 pos = 0; 57 } 58 59 // Start new output file? 60 if ((TT.b && !bytesleft) || (TT.l && !linesleft)) { 61 char *s = TT.outfile + strlen(TT.outfile); 62 63 j = filenum++; 64 for (i = 0; i<TT.a; i++) { 65 *(--s) = 'a'+(j%26); 66 j /= 26; 67 } 68 if (j) error_exit("bad suffix"); 69 bytesleft = TT.b + ((filenum == TT.n) ? st.st_size%TT.n : 0); 70 linesleft = TT.l; 71 xclose(outfd); 72 outfd = xcreate(TT.outfile, O_RDWR|O_CREAT|O_TRUNC, st.st_mode & 0777); 73 } 74 75 // Write next chunk of output. 76 if (TT.l) { 77 for (i = pos; i < len; ) { 78 if (toybuf[i++] == '\n' && !--linesleft) break; 79 if (!--bytesleft) break; 80 } 81 j = i - pos; 82 } else { 83 j = len - pos; 84 if (j > bytesleft) j = bytesleft; 85 bytesleft -= j; 86 } 87 xwrite(outfd, toybuf+pos, j); 88 pos += j; 89 } 90 91 if (CFG_TOYBOX_FREE) { 92 xclose(outfd); 93 if (infd) close(infd); 94 free(TT.outfile); 95 } 96 xexit(); 97} 98 99void split_main(void) 100{ 101 if (!TT.b && !TT.l && !TT.n) TT.l = 1000; 102 103 // Allocate template for output filenames 104 TT.outfile = xmprintf("%s%*c", (toys.optc == 2) ? toys.optargs[1] : "x", 105 (int)TT.a, ' '); 106 107 // We only ever use one input, but this handles '-' or no input for us. 108 loopfiles(toys.optargs, do_split); 109} 110