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#<1n#<1[!bl][!bn][!ln]", 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] [-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
GLOBALS(long n,l,b,a;char * outfile;)31 GLOBALS(
32 long n, l, b, a;
33
34 char *outfile;
35 )
36
37 static 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
split_main(void)99 void 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