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
11 USE_SPLIT(NEWTOY(split, ">2a#<1=2>9b#<1l#<1[!bl]", TOYFLAG_USR|TOYFLAG_BIN))
12
13 config SPLIT
14 bool "split"
15 default y
16 help
17 usage: split [-a SUFFIX_LEN] [-b BYTES] [-l LINES] [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 */
26
27 #define FOR_split
28 #include "toys.h"
29
GLOBALS(long l,b,a;char * outfile;)30 GLOBALS(
31 long l, b, a;
32
33 char *outfile;
34 )
35
36 static void do_split(int infd, char *in)
37 {
38 unsigned long bytesleft, linesleft, filenum, len, pos;
39 int outfd = -1;
40 struct stat st;
41
42 // posix doesn't cover permissions on output file, so copy input (or 0777)
43 st.st_mode = 0777;
44 fstat(infd, &st);
45
46 len = pos = filenum = bytesleft = linesleft = 0;
47 for (;;) {
48 int i, j;
49
50 // Refill toybuf?
51 if (len == pos) {
52 if (!(len = xread(infd, toybuf, sizeof(toybuf)))) break;
53 pos = 0;
54 }
55
56 // Start new output file?
57 if ((TT.b && !bytesleft) || (TT.l && !linesleft)) {
58 char *s = TT.outfile + strlen(TT.outfile);
59
60 j = filenum++;
61 for (i = 0; i<TT.a; i++) {
62 *(--s) = 'a'+(j%26);
63 j /= 26;
64 }
65 if (j) error_exit("bad suffix");
66 bytesleft = TT.b;
67 linesleft = TT.l;
68 if (outfd != -1) close(outfd);
69 outfd = xcreate(TT.outfile, O_RDWR|O_CREAT|O_TRUNC, st.st_mode & 0777);
70 }
71
72 // Write next chunk of output.
73 if (TT.l) {
74 for (i = pos; i < len; ) {
75 if (toybuf[i++] == '\n' && !--linesleft) break;
76 if (!--bytesleft) break;
77 }
78 j = i - pos;
79 } else {
80 j = len - pos;
81 if (j > bytesleft) j = bytesleft;
82 bytesleft -= j;
83 }
84 xwrite(outfd, toybuf+pos, j);
85 pos += j;
86 }
87
88 if (CFG_TOYBOX_FREE) {
89 if (outfd != -1) close(outfd);
90 if (infd) close(infd);
91 free(TT.outfile);
92 }
93 xexit();
94 }
95
split_main(void)96 void split_main(void)
97 {
98 if (!TT.b && !TT.l) TT.l = 1000;
99
100 // Allocate template for output filenames
101 TT.outfile = xmprintf("%s%*c", (toys.optc == 2) ? toys.optargs[1] : "x",
102 (int)TT.a, ' ');
103
104 // We only ever use one input, but this handles '-' or no input for us.
105 loopfiles(toys.optargs, do_split);
106 }
107