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comparison toys/posix/split.c @ 924:b792de46d715

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Implement split.
author Rob Landley <rob@landley.net>
date Sun, 16 Jun 2013 16:37:43 -0500
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children 0752b2d58909
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923:aff9fa1075eb 924:b792de46d715
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", 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
30 GLOBALS(
31 long lines;
32 long bytes;
33 long suflen;
34
35 char *outfile;
36 )
37
38 void do_split(int infd, char *in)
39 {
40 unsigned long bytesleft, linesleft, filenum, len, pos;
41 int outfd = -1;
42 struct stat st;
43
44 // posix doesn't cover permissions on output file, so copy input (or 0777)
45 st.st_mode = 0777;
46 fstat(infd, &st);
47
48 len = pos = filenum = bytesleft = linesleft = 0;
49 for (;;) {
50 int i, j;
51
52 // Refill toybuf?
53 if (len == pos) {
54 if (!(len = xread(infd, toybuf, sizeof(toybuf)))) break;
55 pos = 0;
56 }
57
58 // Start new output file?
59 if ((TT.bytes && !bytesleft) || (TT.lines && !linesleft)) {
60 char *s = TT.outfile + strlen(TT.outfile);
61
62 j = filenum++;
63 for (i = 0; i<TT.suflen; i++) {
64 *(--s) = 'a'+(j%26);
65 j /= 26;
66 }
67 if (j) error_exit("bad suffix");
68 bytesleft = TT.bytes;
69 linesleft = TT.lines;
70 if (outfd != -1) close(outfd);
71 outfd = xcreate(TT.outfile, O_RDWR|O_CREAT|O_TRUNC, st.st_mode & 0777);
72 }
73
74 // Write next chunk of output.
75 if (TT.lines) {
76 for (i = pos; i < len; ) {
77 if (toybuf[i++] == '\n' && !--linesleft) break;
78 if (!--bytesleft) break;
79 }
80 j = i - pos;
81 } else {
82 j = len - pos;
83 if (j > bytesleft) j = bytesleft;
84 bytesleft -= j;
85 }
86 xwrite(outfd, toybuf+pos, j);
87 pos += j;
88 }
89
90 if (CFG_TOYBOX_FREE) {
91 if (outfd != -1) close(outfd);
92 if (infd) close(infd);
93 free(TT.outfile);
94 }
95 xexit();
96 }
97
98 void split_main(void)
99 {
100 if (!TT.bytes && !TT.lines) TT.lines = 1000;
101
102 // Allocate template for output filenames
103 TT.outfile = xmsprintf("%s% *c", (toys.optc == 2) ? toys.optargs[1] : "x",
104 (int)TT.suflen, ' ');
105
106 // We only ever use one input, but this handles '-' or no input for us.
107 loopfiles(toys.optargs, do_split);
108 }