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	dd.c - sbase - suckless unix tools
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	dd.c (4895B)
	---
	1 /* See LICENSE file for copyright and license details. */
	2 #include <ctype.h>
	3 #include <fcntl.h>
	4 #include <inttypes.h>
	5 #include <stdint.h>
	6 #include <string.h>
	7 #include <unistd.h>
	8
	9 #include "util.h"
	10
	11 static off_t ifull, ofull, ipart, opart;
	12
	13 static void
	14 usage(void)
	15 {
	16 eprintf("usage: %s [operand...]\n", argv0);
	17 }
	18
	19 static size_t
	20 parsesize(char *expr)
	21 {
	22 char *s = expr;
	23 size_t n = 1;
	24
	25 for (;;) {
	26 n *= strtoumax(s, &s, 10);
	27 switch (*s) {
	28 case 'k': n <<= 10; s++; break;
	29 case 'b': n <<= 9; s++; break;
	30 }
	31 if (*s != 'x' \|\| !s[1])
	32 break;
	33 s++;
	34 }
	35 if (*s \|\| n == 0)
	36 eprintf("invalid block size expression '%s'\n", expr);
	37
	38 return n;
	39 }
	40
	41 static void
	42 bswap(unsigned char *buf, size_t len)
	43 {
	44 int c;
	45
	46 for (len &= ~1; len > 0; buf += 2, len -= 2) {
	47 c = buf[0];
	48 buf[0] = buf[1];
	49 buf[1] = c;
	50 }
	51 }
	52
	53 static void
	54 lcase(unsigned char *buf, size_t len)
	55 {
	56 for (; len > 0; buf++, len--)
	57 buf[0] = tolower(buf[0]);
	58 }
	59
	60 static void
	61 ucase(unsigned char *buf, size_t len)
	62 {
	63 for (; len > 0; buf++, len--)
	64 buf[0] = toupper(buf[0]);
	65 }
	66
	67 static void
	68 summary(void)
	69 {
	70 fprintf(stderr, "%"PRIdMAX"+%"PRIdMAX" records in\n", (intmax_t)…
	71 fprintf(stderr, "%"PRIdMAX"+%"PRIdMAX" records out\n", (intmax_t…
	72 }
	73
	74 int
	75 main(int argc, char *argv[])
	76 {
	77 enum {
	78 LCASE = 1 << 0,
	79 UCASE = 1 << 1,
	80 SWAB = 1 << 2,
	81 NOERROR = 1 << 3,
	82 NOTRUNC = 1 << 4,
	83 SYNC = 1 << 5,
	84 } conv = 0;
	85 char arg, val, *end;
	86 const char iname = "-", oname = "-";
	87 int ifd = 0, ofd = 1, eof = 0;
	88 size_t len, bs = 0, ibs = 512, obs = 512, ipos = 0, opos = 0;
	89 off_t skip = 0, seek = 0, count = -1;
	90 ssize_t ret;
	91 unsigned char *buf;
	92
	93 argv0 = argc ? (argc--, *argv++) : "dd";
	94 for (; argc > 0; argc--, argv++) {
	95 arg = *argv;
	96 val = strchr(arg, '=');
	97 if (!val)
	98 usage();
	99 *val++ = '\0';
	100 if (strcmp(arg, "if") == 0) {
	101 iname = val;
	102 } else if (strcmp(arg, "of") == 0) {
	103 oname = val;
	104 } else if (strcmp(arg, "ibs") == 0) {
	105 ibs = parsesize(val);
	106 } else if (strcmp(arg, "obs") == 0) {
	107 obs = parsesize(val);
	108 } else if (strcmp(arg, "bs") == 0) {
	109 bs = parsesize(val);
	110 } else if (strcmp(arg, "skip") == 0) {
	111 skip = estrtonum(val, 0, LLONG_MAX);
	112 } else if (strcmp(arg, "seek") == 0) {
	113 seek = estrtonum(val, 0, LLONG_MAX);
	114 } else if (strcmp(arg, "count") == 0) {
	115 count = estrtonum(val, 0, LLONG_MAX);
	116 } else if (strcmp(arg, "conv") == 0) {
	117 do {
	118 end = strchr(val, ',');
	119 if (end)
	120 *end++ = '\0';
	121 if (strcmp(val, "lcase") == 0)
	122 conv \|= LCASE;
	123 else if (strcmp(val, "ucase") == 0)
	124 conv \|= UCASE;
	125 else if (strcmp(val, "swab") == 0)
	126 conv \|= SWAB;
	127 else if (strcmp(val, "noerror") == 0)
	128 conv \|= NOERROR;
	129 else if (strcmp(val, "notrunc") == 0)
	130 conv \|= NOTRUNC;
	131 else if (strcmp(val, "sync") == 0)
	132 conv \|= SYNC;
	133 else
	134 eprintf("unknown conv flag '%s'\…
	135 val = end;
	136 } while (val);
	137 } else {
	138 weprintf("unknown operand '%s'\n", arg);
	139 usage();
	140 }
	141 }
	142
	143 if (bs)
	144 ibs = obs = bs;
	145 if (strcmp(iname, "-") != 0) {
	146 ifd = open(iname, O_RDONLY);
	147 if (ifd < 0)
	148 eprintf("open %s:", iname);
	149 }
	150 if (strcmp(oname, "-") != 0) {
	151 ofd = open(oname, O_WRONLY \| O_CREAT \| (conv & NOTRUNC \|…
	152 if (ofd < 0)
	153 eprintf("open %s:", oname);
	154 }
	155
	156 len = MAX(ibs, obs) + ibs;
	157 buf = emalloc(len);
	158 if (skip && lseek(ifd, skip * ibs, SEEK_SET) < 0) {
	159 while (skip--) {
	160 ret = read(ifd, buf, ibs);
	161 if (ret < 0)
	162 eprintf("read:");
	163 if (ret == 0) {
	164 eof = 1;
	165 break;
	166 }
	167 }
	168 }
	169 if (seek) {
	170 if (!(conv & NOTRUNC) && ftruncate(ofd, seek * ibs) != 0)
	171 eprintf("ftruncate:");
	172 if (lseek(ofd, seek * ibs, SEEK_SET) < 0)
	173 eprintf("lseek:");
	174 /* XXX: handle non-seekable files */
	175 }
	176 while (!eof) {
	177 while (ipos - opos < obs) {
	178 if (ifull + ipart == count) {
	179 eof = 1;
	180 break;
	181 }
	182 ret = read(ifd, buf + ipos, ibs);
	183 if (ret == 0) {
	184 eof = 1;
	185 break;
	186 }
	187 if (ret < 0) {
	188 weprintf("read:");
	189 if (!(conv & NOERROR))
	190 return 1;
	191 summary();
	192 if (!(conv & SYNC))
	193 continue;
	194 ret = 0;
	195 }
	196 if (ret < ibs) {
	197 ipart++;
	198 if (conv & SYNC) {
	199 memset(buf + ipos + ret, 0, ibs …
	200 ret = ibs;
	201 }
	202 } else {
	203 ifull++;
	204 }
	205 if (conv & SWAB)
	206 bswap(buf + ipos, ret);
	207 if (conv & LCASE)
	208 lcase(buf + ipos, ret);
	209 if (conv & UCASE)
	210 ucase(buf + ipos, ret);
	211 ipos += ret;
	212 if (bs && !(conv & (SWAB \| LCASE \| UCASE)))
	213 break;
	214 }
	215 if (ipos == opos)
	216 break;
	217 do {
	218 ret = write(ofd, buf + opos, MIN(obs, ipos - opo…
	219 if (ret < 0)
	220 eprintf("write:");
	221 if (ret == 0)
	222 eprintf("write returned 0\n");
	223 if (ret < obs)
	224 opart++;
	225 else
	226 ofull++;
	227 opos += ret;
	228 } while (ipos - opos >= (eof ? 1 : obs));
	229 if (opos < ipos)
	230 memmove(buf, buf + opos, ipos - opos);
	231 ipos -= opos;
	232 opos = 0;
	233 }
	234 summary();
	235
	236 return 0;
	237 }