[BusyBox] new dd
Matt Kraai
kraai at alumni.carnegiemellon.edu
Thu Dec 14 21:54:23 UTC 2000
Howdy,
I rewrote dd.
Advantages of the new version?
* It checks the return values of all system calls.
* You don't have to press ^D twice when it reads from stdin.
* It doesn't print the summary to stdout if the file was printed
to stdout.
* It is anal about its arguments.
* It fixes the suffixes of tail -n.
* dd.o shrinks by 49 bytes.
Disadvantages?
* utility.o grows by 49 bytes.
* tail.o grows by 22 bytes.
* It is 22 bytes bigger overall.
* I wrote it.
The patch is attached. Should I commit it (or send it down the
path of nl, tac, and rev)?
Matt
-------------- next part --------------
Index: dd.c
===================================================================
RCS file: /var/cvs/busybox/dd.c,v
retrieving revision 1.36
diff -u -r1.36 dd.c
--- dd.c 2000/12/07 19:56:48 1.36
+++ dd.c 2000/12/14 20:56:15
@@ -2,16 +2,9 @@
/*
* Mini dd implementation for busybox
*
- * Copyright (C) 1999, 2000 by Lineo, inc.
- * Written by Erik Andersen <andersen at lineo.com>, <andersee at debian.org>
*
- * Based in part on code taken from sash.
- * Copyright (c) 1999 by David I. Bell
- * Permission is granted to use, distribute, or modify this source,
- * provided that this copyright notice remains intact.
+ * Copyright (C) 2000 by Matt Kraai <kraai at alumni.carnegiemellon.edu>
*
- * Permission to distribute this code under the GPL has been granted.
- *
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
@@ -28,154 +21,139 @@
*
*/
-
#include "busybox.h"
-#include <features.h>
-#include <stdio.h>
+
+#include <sys/types.h>
#include <fcntl.h>
-#include <errno.h>
-#if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1)
-#include <inttypes.h>
-#else
-typedef unsigned long long int uintmax_t;
-#endif
+
+static struct suffix_mult dd_suffixes[] = {
+ { "c", 1 },
+ { "w", 2 },
+ { "b", 512 },
+ { "kD", 1000 },
+ { "k", 1024 },
+ { "MD", 1000000 },
+ { "M", 1048576 },
+ { "GD", 1000000000 },
+ { "G", 1073741824 },
+ { NULL, 0 }
+};
-extern int dd_main(int argc, char **argv)
+ssize_t safe_read(int fd, void *buf, size_t count)
{
- char *inFile = NULL;
- char *outFile = NULL;
- int inFd;
- int outFd;
- int inCc = 0;
- int outCc;
- int trunc=TRUE;
- int sync=FALSE;
- long blockSize = 512,ibs;
- uintmax_t skipBlocks = 0;
- uintmax_t seekBlocks = 0;
- uintmax_t count = (uintmax_t) - 1;
- uintmax_t inTotal = 0;
- uintmax_t outTotal = 0;
- uintmax_t totalSize;
-
- unsigned char buf[BUFSIZ];
- char *keyword = NULL;
-
- argc--;
- argv++;
-
- /* Parse any options */
- while (argc) {
- if (inFile == NULL && (strncmp(*argv, "if", 2) == 0))
- inFile = ((strchr(*argv, '=')) + 1);
- else if (outFile == NULL && (strncmp(*argv, "of", 2) == 0))
- outFile = ((strchr(*argv, '=')) + 1);
- else if (strncmp("count", *argv, 5) == 0) {
- count = atoi_w_units((strchr(*argv, '=')) + 1);
- if (count < 0) {
- error_msg("Bad count value %s\n", *argv);
- goto usage;
- }
- } else if (strncmp(*argv, "bs", 2) == 0) {
- blockSize = atoi_w_units((strchr(*argv, '=')) + 1);
- if (blockSize <= 0) {
- error_msg("Bad block size value %s\n", *argv);
- goto usage;
- }
- } else if (strncmp(*argv, "skip", 4) == 0) {
- skipBlocks = atoi_w_units((strchr(*argv, '=')) + 1);
- if (skipBlocks <= 0) {
- error_msg("Bad skip value %s\n", *argv);
- goto usage;
- }
+ ssize_t n;
- } else if (strncmp(*argv, "seek", 4) == 0) {
- seekBlocks = atoi_w_units((strchr(*argv, '=')) + 1);
- if (seekBlocks <= 0) {
- error_msg("Bad seek value %s\n", *argv);
- goto usage;
+ do {
+ n = read(fd, buf, count);
+ } while (n < 0 && errno == EINTR);
+
+ return n;
+}
+
+int dd_main(int argc, char **argv)
+{
+ int i, ifd, ofd, sync = FALSE, trunc = TRUE;
+ size_t in_full = 0, in_part = 0, out_full = 0, out_part = 0;
+ size_t bs = 512, count = -1;
+ ssize_t n;
+ off_t seek = 0, skip = 0;
+ FILE *statusfp;
+ char *infile = NULL, *outfile = NULL, *buf;
+
+ for (i = 1; i < argc; i++) {
+ if (strncmp("bs=", argv[i], 3) == 0)
+ bs = parse_number(argv[i]+3, dd_suffixes);
+ else if (strncmp("count=", argv[i], 6) == 0)
+ count = parse_number(argv[i]+6, dd_suffixes);
+ else if (strncmp("seek=", argv[i], 5) == 0)
+ seek = parse_number(argv[i]+5, dd_suffixes);
+ else if (strncmp("skip=", argv[i], 5) == 0)
+ skip = parse_number(argv[i]+5, dd_suffixes);
+ else if (strncmp("if=", argv[i], 3) == 0)
+ infile = argv[i]+3;
+ else if (strncmp("of=", argv[i], 3) == 0)
+ outfile = argv[i]+3;
+ else if (strncmp("conv=", argv[i], 5) == 0) {
+ buf = argv[i]+5;
+ while (1) {
+ if (strncmp("notrunc", buf, 7) == 0) {
+ trunc = FALSE;
+ buf += 7;
+ } else if (strncmp("sync", buf, 4) == 0) {
+ sync = TRUE;
+ buf += 4;
+ } else {
+ error_msg_and_die("invalid conversion `%s'", argv[i]+5);
+ }
+ if (buf[0] == '\0')
+ break;
+ if (buf[0] == ',')
+ buf++;
}
- } else if (strncmp(*argv, "conv", 4) == 0) {
- keyword = (strchr(*argv, '=') + 1);
- if (strcmp(keyword, "notrunc") == 0)
- trunc=FALSE;
- if (strcmp(keyword, "sync") == 0)
- sync=TRUE;
- } else {
- goto usage;
- }
- argc--;
- argv++;
+ } else
+ usage(dd_usage);
}
- if (inFile == NULL)
- inFd = fileno(stdin);
- else
- inFd = open(inFile, 0);
-
- if (inFd < 0) {
- /* Note that we are not freeing buf or closing
- * files here to save a few bytes. This exits
- * here anyways... */
-
- /* free(buf); */
- perror_msg_and_die("%s", inFile);
- }
-
- if (outFile == NULL)
- outFd = fileno(stdout);
- else
- outFd = open(outFile, O_WRONLY | O_CREAT, 0666);
-
- if (outFd < 0) {
- /* Note that we are not freeing buf or closing
- * files here to save a few bytes. This exits
- * here anyways... */
-
- /* close(inFd);
- free(buf); */
- perror_msg_and_die("%s", outFile);
- }
-
- lseek(inFd, (off_t) (skipBlocks * blockSize), SEEK_SET);
- lseek(outFd, (off_t) (seekBlocks * blockSize), SEEK_SET);
- totalSize=count*blockSize;
-
- ibs=blockSize;
- if (ibs > BUFSIZ)
- ibs=BUFSIZ;
-
- while (totalSize > outTotal) {
- inCc = full_read(inFd, buf, ibs);
- inTotal += inCc;
- if ( (sync==TRUE) && (inCc>0) )
- while (inCc<ibs)
- buf[inCc++]='\0';
-
- if ((outCc = full_write(outFd, buf, inCc)) < 1){
- if (outCc < 0 ){
- perror("Error during write");
- }
+ buf = xmalloc(bs);
+
+ if (infile != NULL) {
+ if ((ifd = open(infile, O_RDONLY)) < 0)
+ perror_msg_and_die("%s", infile);
+ } else {
+ ifd = STDIN_FILENO;
+ infile = "standard input";
+ }
+
+ if (outfile != NULL) {
+ if ((ofd = open(outfile, O_WRONLY | O_CREAT, 0666)) < 0)
+ perror_msg_and_die("%s", outfile);
+ statusfp = stdout;
+ } else {
+ ofd = STDOUT_FILENO;
+ outfile = "standard output";
+ statusfp = stderr;
+ }
+
+ if (skip) {
+ if (lseek(ifd, skip * bs, SEEK_CUR) < 0)
+ perror_msg_and_die("%s", infile);
+ }
+
+ if (seek) {
+ if (lseek(ofd, seek * bs, SEEK_CUR) < 0)
+ perror_msg_and_die("%s", outfile);
+ }
+
+ if (trunc) {
+ if (ftruncate(ofd, seek * bs) < 0)
+ perror_msg_and_die("%s", outfile);
+ }
+
+ while (in_full + in_part != count) {
+ n = safe_read(ifd, buf, bs);
+ if (n < 0)
+ perror_msg_and_die("%s", infile);
+ if (n == 0)
break;
+ if (n == bs)
+ in_full++;
+ else
+ in_part++;
+ if (sync) {
+ memset(buf + n, '\0', bs - n);
+ n = bs;
}
- outTotal += outCc;
- }
- if (trunc == TRUE) {
- ftruncate(outFd, lseek(outFd, 0, SEEK_CUR));
- }
- /* Note that we are not freeing memory or closing
- * files here, to save a few bytes. */
-#ifdef BB_FEATURE_CLEAN_UP
- close(inFd);
- close(outFd);
-#endif
-
- printf("%ld+%d records in\n", (long) (inTotal / blockSize),
- (inTotal % blockSize) != 0);
- printf("%ld+%d records out\n", (long) (outTotal / blockSize),
- (outTotal % blockSize) != 0);
- return EXIT_SUCCESS;
- usage:
+ n = full_write(ofd, buf, n);
+ if (n < 0)
+ perror_msg_and_die("%s", outfile);
+ if (n == bs)
+ out_full++;
+ else
+ out_part++;
+ }
+
+ fprintf(statusfp, "%d+%d records in\n", in_full, in_part);
+ fprintf(statusfp, "%d+%d records out\n", out_full, out_part);
- usage(dd_usage);
+ return EXIT_SUCCESS;
}
Index: tail.c
===================================================================
RCS file: /var/cvs/busybox/tail.c,v
retrieving revision 1.27
diff -u -r1.27 tail.c
--- tail.c 2000/12/07 19:56:48 1.27
+++ tail.c 2000/12/14 21:08:57
@@ -61,6 +61,13 @@
static off_t units=0;
+static struct suffix_mult tail_suffixes[] = {
+ { "b", 512 },
+ { "k", 1024 },
+ { "m", 1048576 },
+ { NULL, 0 }
+};
+
static int tail_stream(int fd)
{
ssize_t startpoint;
@@ -170,32 +177,6 @@
switch (opt) {
#ifndef BB_FEATURE_SIMPLE_TAIL
- case 'c':
- unit_type = BYTES;
- test = atoi(optarg);
- if(test==0)
- usage(tail_usage);
- if(optarg[strlen(optarg)-1]>'9') {
- switch (optarg[strlen(optarg)-1]) {
- case 'b':
- test *= 512;
- break;
- case 'k':
- test *= 1024;
- break;
- case 'm':
- test *= (1024 * 1024);
- break;
- default:
- fprintf(stderr,"Size must be b,k, or m.");
- usage(tail_usage);
- }
- }
- if(optarg[0]=='+')
- units=test+1;
- else
- units=-(test+1);
- break;
case 'q':
show_headers = 0;
break;
@@ -207,15 +188,12 @@
case 'v':
verbose = 1;
break;
+ case 'c':
+ unit_type = BYTES;
+ /* FALLS THROUGH */
#endif
- case 'f':
- follow = 1;
- break;
- case 'h':
- usage(tail_usage);
- break;
case 'n':
- test = atoi(optarg);
+ test = parse_number(optarg, tail_suffixes);
if (test) {
if (optarg[0] == '+')
units = test;
@@ -223,6 +201,12 @@
units = -(test+1);
} else
usage(tail_usage);
+ break;
+ case 'f':
+ follow = 1;
+ break;
+ case 'h':
+ usage(tail_usage);
break;
default:
error_msg("\nUnknown arg: %c.\n\n",optopt);
Index: utility.c
===================================================================
RCS file: /var/cvs/busybox/utility.c,v
retrieving revision 1.173
diff -u -r1.173 utility.c
--- utility.c 2000/12/13 01:52:39 1.173
+++ utility.c 2000/12/14 20:56:15
@@ -1215,58 +1215,6 @@
}
#endif /* BB_DF || BB_MTAB */
-
-
-#if defined BB_DD || defined BB_TAIL
-/*
- * Read a number with a possible multiplier.
- * Returns -1 if the number format is illegal.
- */
-extern long atoi_w_units(const char *cp)
-{
- long value;
-
- if (!is_decimal(*cp))
- return -1;
-
- value = 0;
-
- while (is_decimal(*cp))
- value = value * 10 + *cp++ - '0';
-
- switch (*cp++) {
- case 'M':
- case 'm': /* `tail' uses it traditionally */
- value *= 1048576;
- break;
-
- case 'k':
- value *= 1024;
- break;
-
- case 'b':
- value *= 512;
- break;
-
- case 'w':
- value *= 2;
- break;
-
- case '\0':
- return value;
-
- default:
- return -1;
- }
-
- if (*cp)
- return -1;
-
- return value;
-}
-#endif /* BB_DD || BB_TAIL */
-
-
#if defined BB_INIT || defined BB_SYSLOGD
/* try to open up the specified device */
extern int device_open(char *device, int mode)
@@ -1790,6 +1738,33 @@
return strcmp(applet1->name, applet2->name);
}
+
+#if defined BB_DD || defined BB_TAIL
+unsigned long int parse_number(const char *numstr, struct suffix_mult *suffixes)
+{
+ struct suffix_mult *sm;
+ unsigned long int ret;
+ int len;
+ char *end;
+
+ ret = strtoul(numstr, &end, 10);
+ if (numstr == end)
+ error_msg_and_die("invalid number `%s'", numstr);
+ while (end[0] != '\0') {
+ for (sm = suffixes; sm->suffix != NULL; sm++) {
+ len = strlen(sm->suffix);
+ if (strncmp(sm->suffix, end, len) == 0) {
+ ret *= sm->mult;
+ end += len;
+ break;
+ }
+ }
+ if (sm->suffix == NULL)
+ error_msg_and_die("invalid number `%s'", numstr);
+ }
+ return ret;
+}
+#endif
/* END CODE */
/*
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