find: improve usage text (Natanael Copa <natanael.copa@gmail.com>)
[oweals/busybox.git] / coreutils / dd.c
index a2dc1c396917e5f8e94cdc793c51e686c3e4bef6..518c5fed26876b013bcce3fdd65789a1b17680cd 100644 (file)
+/* vi: set sw=4 ts=4: */
 /*
  * Mini dd implementation for busybox
  *
- * Copyright (C) 1999 by Lineo, inc.
- * Written by Erik Andersen <andersen@lineo.com>, <andersee@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.
- *
- * 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
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * Copyright (C) 2000,2001  Matt Kraai
  *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-
-#include "internal.h"
-#include <features.h>
-#include <stdio.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 const char dd_usage[] =
-"dd [if=name] [of=name] [bs=n] [count=n]\n\n"
-"Copy a file, converting and formatting according to options\n\n"
-"\tif=FILE\tread from FILE instead of stdin\n"
-"\tof=FILE\twrite to FILE instead of stout\n"
-"\tbs=n\tread and write N BYTES at a time\n"
-"\tcount=n\tcopy only n input blocks\n"
-//"\tskip=n\tskip n input blocks\n"
-"\n"
-"BYTES may be suffixed: by k for x1024, b for x512, and w for x2.\n";
-
-
-
-
-/*
- * Read a number with a possible multiplier.
- * Returns -1 if the number format is illegal.
- */
-static long getNum (const char *cp)
+#include "busybox.h"
+#include <signal.h>  /* For FEATURE_DD_SIGNAL_HANDLING */
+
+static const struct suffix_mult dd_suffixes[] = {
+       { "c", 1 },
+       { "w", 2 },
+       { "b", 512 },
+       { "kD", 1000 },
+       { "k", 1024 },
+       { "K", 1024 },  /* compat with coreutils dd */
+       { "MD", 1000000 },
+       { "M", 1048576 },
+       { "GD", 1000000000 },
+       { "G", 1073741824 },
+       { NULL, 0 }
+};
+
+struct globals {
+       off_t out_full, out_part, in_full, in_part;
+};
+#define G (*(struct globals*)&bb_common_bufsiz1)
+
+static void dd_output_status(int ATTRIBUTE_UNUSED cur_signal)
 {
-    long value;
-
-    if (!isDecimal (*cp))
-       return -1;
-
-    value = 0;
-
-    while (isDecimal (*cp))
-       value = value * 10 + *cp++ - '0';
-
-    switch (*cp++) {
-    case 'k':
-       value *= 1024;
-       break;
-
-    case 'b':
-       value *= 512;
-       break;
-
-    case 'w':
-       value *= 2;
-       break;
-
-    case '\0':
-       return value;
-
-    default:
-       return -1;
-    }
+       fprintf(stderr, "%"OFF_FMT"d+%"OFF_FMT"d records in\n"
+                       "%"OFF_FMT"d+%"OFF_FMT"d records out\n",
+                       G.in_full, G.in_part,
+                       G.out_full, G.out_part);
+}
 
-    if (*cp)
-       return -1;
+static ssize_t full_write_or_warn(int fd, const void *buf, size_t len,
+       const char * const filename)
+{
+       ssize_t n = full_write(fd, buf, len);
+       if (n < 0)
+               bb_perror_msg("writing '%s'", filename);
+       return n;
+}
 
-    return value;
+static bool write_and_stats(int fd, const void *buf, size_t len, size_t obs,
+       const char * const filename)
+{
+       ssize_t n = full_write_or_warn(fd, buf, len, filename);
+       if (n < 0)
+               return 1;
+       if (n == obs)
+               G.out_full++;
+       else if (n > 0)
+               G.out_part++;
+       return 0;
 }
 
+#if ENABLE_LFS
+#define XATOU_SFX xatoull_sfx
+#else
+#define XATOU_SFX xatoul_sfx
+#endif
 
-extern int dd_main (int argc, char **argv)
+int dd_main(int argc, char **argv);
+int dd_main(int argc, char **argv)
 {
-    const char *inFile = NULL;
-    const char *outFile = NULL;
-    char *cp;
-    int inFd;
-    int outFd;
-    int inCc = 0;
-    int outCc;
-    size_t blockSize = 512;
-    //uintmax_t skipBlocks = 0;
-    uintmax_t count = (uintmax_t)-1;
-    uintmax_t intotal;
-    uintmax_t outTotal;
-    unsigned char *buf;
-
-    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 = getNum ((strchr(*argv, '='))+1);
-           if (count <= 0) {
-               fprintf (stderr, "Bad count value %s\n", *argv);
-               goto usage;
-           }
-       }
-       else if (strncmp(*argv, "bs", 2) == 0) {
-           blockSize = getNum ((strchr(*argv, '='))+1);
-           if (blockSize <= 0) {
-               fprintf (stderr, "Bad block size value %s\n", *argv);
-               goto usage;
-           }
+       enum {
+               sync_flag    = 1 << 0,
+               noerror      = 1 << 1,
+               trunc_flag   = 1 << 2,
+               twobufs_flag = 1 << 3,
+       };
+       const char * const keywords[] = {
+               "bs=", "count=", "seek=", "skip=", "if=", "of=",
+#if ENABLE_FEATURE_DD_IBS_OBS
+               "ibs=", "obs=", "conv=", "notrunc", "sync", "noerror",
+#endif
+               NULL
+       };
+#define OP_bs          0 + 1
+#define OP_count       OP_bs + 1
+#define OP_seek                OP_count + 1
+#define OP_skip                OP_seek + 1
+#define OP_if          OP_skip + 1
+#define OP_of          OP_if + 1
+#define OP_ibs         OP_of + ENABLE_FEATURE_DD_IBS_OBS
+#define OP_obs         OP_ibs + ENABLE_FEATURE_DD_IBS_OBS
+#define OP_conv                OP_obs + ENABLE_FEATURE_DD_IBS_OBS
+#define OP_conv_notrunc        OP_conv + ENABLE_FEATURE_DD_IBS_OBS
+#define OP_conv_sync   OP_conv_notrunc + ENABLE_FEATURE_DD_IBS_OBS
+#define OP_conv_noerror        OP_conv_sync + ENABLE_FEATURE_DD_IBS_OBS
+
+       int flags = trunc_flag;
+       size_t oc = 0, ibs = 512, obs = 512;
+       ssize_t n, w;
+       off_t seek = 0, skip = 0, count = OFF_T_MAX;
+       int ifd, ofd;
+       const char *infile = NULL, *outfile = NULL;
+       char *ibuf, *obuf;
+
+       if (ENABLE_FEATURE_DD_SIGNAL_HANDLING) {
+               struct sigaction sa;
+
+               memset(&sa, 0, sizeof(sa));
+               sa.sa_handler = dd_output_status;
+               sa.sa_flags = SA_RESTART;
+               sigemptyset(&sa.sa_mask);
+               sigaction(SIGUSR1, &sa, 0);
        }
-#if 0
-       else if (strncmp(*argv, "skip", 4) == 0) {
-           skipBlocks = atoi( *argv); 
-           if (skipBlocks <= 0) {
-               fprintf (stderr, "Bad skip value %d\n", skipBlocks);
-               goto usage;
-           }
 
+       for (n = 1; n < argc; n++) {
+               smalluint key_len, what;
+               char *key;
+               char *arg = argv[n];
+
+//XXX:FIXME: we reject plain "dd --" This would cost ~20 bytes, so..
+//if (*arg == '-' && *++arg == '-' && !*++arg) continue;
+               key = strstr(arg, "=");
+               if (key == NULL)
+                       bb_show_usage();
+               key_len = key - arg + 1;
+               key = xstrndup(arg, key_len);
+               what = index_in_str_array(keywords, key) + 1;
+               if (ENABLE_FEATURE_CLEAN_UP)
+                       free(key);
+               if (what == 0)
+                       bb_show_usage();
+               arg += key_len;
+               /* Must fit into positive ssize_t */
+               if (ENABLE_FEATURE_DD_IBS_OBS) {
+                       if (what == OP_ibs) {
+                               ibs = xatoul_range_sfx(arg, 1, ((size_t)-1L)/2, dd_suffixes);
+                               continue;
+                       }
+                       if (what == OP_obs) {
+                               obs = xatoul_range_sfx(arg, 1, ((size_t)-1L)/2, dd_suffixes);
+                               continue;
+                       }
+                       if (what == OP_conv) {
+                               while (1) {
+                                       /* find ',', replace them with nil so we can use arg for
+                                        * index_in_str_array without copying.
+                                        * We rely on arg being non-null, else strstr would fault.
+                                        */
+                                       key = strstr(arg, ",");
+                                       if (key)
+                                               *key = '\0';
+                                       what = index_in_str_array(keywords, arg) + 1;
+                                       if (what < OP_conv_notrunc)
+                                               bb_error_msg_and_die(bb_msg_invalid_arg, arg, "conv");
+                                       if (what == OP_conv_notrunc)
+                                               flags &= ~trunc_flag;
+                                       if (what == OP_conv_sync)
+                                               flags |= sync_flag;
+                                       if (what == OP_conv_noerror)
+                                               flags |= noerror;
+                                       if (!key) /* no ',' left, so this was the last specifier */
+                                               break;
+                                       arg += key - arg + 1; /* skip this keyword plus ',' */
+                               }
+                               continue;
+                       }
+               }
+               if (what == OP_bs) {
+                       ibs = obs = xatoul_range_sfx(arg, 1, ((size_t)-1L)/2, dd_suffixes);
+                       continue;
+               }
+               /* These can be large: */
+               if (what == OP_count) {
+                       count = XATOU_SFX(arg, dd_suffixes);
+                       continue;
+               }
+               if (what == OP_seek) {
+                       seek = XATOU_SFX(arg, dd_suffixes);
+                       continue;
+               }
+               if (what == skip) {
+                       skip = XATOU_SFX(arg, dd_suffixes);
+                       continue;
+               }
+               if (what == OP_if) {
+                       infile = arg;
+                       continue;
+               }
+               if (what == OP_of)
+                       outfile = arg;
        }
-#endif
+//XXX:FIXME for huge ibs or obs, malloc'ing them isn't the brightest idea ever
+       ibuf = obuf = xmalloc(ibs);
+       if (ibs != obs) {
+               flags |= twobufs_flag;
+               obuf = xmalloc(obs);
+       }
+       if (infile != NULL)
+               ifd = xopen(infile, O_RDONLY);
        else {
-           goto usage;
+               ifd = STDIN_FILENO;
+               infile = bb_msg_standard_input;
+       }
+       if (outfile != NULL) {
+               int oflag = O_WRONLY | O_CREAT;
+
+               if (!seek && (flags & trunc_flag))
+                       oflag |= O_TRUNC;
+
+               ofd = xopen(outfile, oflag);
+
+               if (seek && (flags & trunc_flag)) {
+                       if (ftruncate(ofd, seek * obs) < 0) {
+                               struct stat st;
+
+                               if (fstat(ofd, &st) < 0 || S_ISREG(st.st_mode) ||
+                                               S_ISDIR(st.st_mode))
+                                       goto die_outfile;
+                       }
+               }
+       } else {
+               ofd = STDOUT_FILENO;
+               outfile = bb_msg_standard_output;
        }
-       argc--;
-       argv++;
-    }
-
-    buf = malloc (blockSize);
-    if (buf == NULL) {
-       fprintf (stderr, "Cannot allocate buffer\n");
-       exit( FALSE);
-    }
-
-    intotal = 0;
-    outTotal = 0;
-
-    if (inFile == NULL)
-       inFd = fileno(stdin);
-    else
-       inFd = open (inFile, 0);
-
-    if (inFd < 0) {
-       perror (inFile);
-       free (buf);
-       exit( FALSE);
-    }
-
-    if (outFile == NULL)
-       outFd = fileno(stdout);
-    else
-       outFd = creat (outFile, 0666);
-
-    if (outFd < 0) {
-       perror (outFile);
-       close (inFd);
-       free (buf);
-       exit( FALSE);
-    }
-
-    //lseek(inFd, skipBlocks*blockSize, SEEK_SET);
-    while (outTotal < count * blockSize) {
-       inCc = read (inFd, buf, blockSize);
-       if (inCc < 0) {
-           perror (inFile);
-           goto cleanup;
-       } else if (inCc == 0) {
-           goto cleanup;
+       if (skip) {
+               if (lseek(ifd, skip * ibs, SEEK_CUR) < 0) {
+                       while (skip-- > 0) {
+                               n = safe_read(ifd, ibuf, ibs);
+                               if (n < 0)
+                                       goto die_infile;
+                               if (n == 0)
+                                       break;
+                       }
+               }
        }
-       intotal += inCc;
-       cp = buf;
-
-       while (intotal > outTotal) {
-           if (outTotal + inCc > count * blockSize)
-               inCc = count * blockSize - outTotal;
-           outCc = write (outFd, cp, inCc);
-           if (outCc < 0) {
-               perror (outFile);
-               goto cleanup;
-           } else if (outCc == 0) {
-               goto cleanup;
-           }
-
-           inCc -= outCc;
-           cp += outCc;
-           outTotal += outCc;
+       if (seek) {
+               if (lseek(ofd, seek * obs, SEEK_CUR) < 0)
+                       goto die_outfile;
        }
-    }
 
-    if (inCc < 0)
-       perror (inFile);
+       while (G.in_full + G.in_part != count) {
+               if (flags & noerror) /* Pre-zero the buffer when for noerror */
+                       memset(ibuf, '\0', ibs);
+               n = safe_read(ifd, ibuf, ibs);
+               if (n == 0)
+                       break;
+               if (n < 0) {
+                       if (flags & noerror) {
+                               n = ibs;
+                               bb_perror_msg("%s", infile);
+                       } else
+                               goto die_infile;
+               }
+               if ((size_t)n == ibs)
+                       G.in_full++;
+               else {
+                       G.in_part++;
+                       if (flags & sync_flag) {
+                               memset(ibuf + n, '\0', ibs - n);
+                               n = ibs;
+                       }
+               }
+               if (flags & twobufs_flag) {
+                       char *tmp = ibuf;
+                       while (n) {
+                               size_t d = obs - oc;
+
+                               if (d > n)
+                                       d = n;
+                               memcpy(obuf + oc, tmp, d);
+                               n -= d;
+                               tmp += d;
+                               oc += d;
+                               if (oc == obs) {
+                                       if (write_and_stats(ofd, obuf, obs, obs, outfile))
+                                               goto out_status;
+                                       oc = 0;
+                               }
+                       }
+               } else
+                       if (write_and_stats(ofd, ibuf, n, obs, outfile))
+                               goto out_status;
+       }
 
-  cleanup:
-    close (inFd);
-    close (outFd);
-    free (buf);
+       if (ENABLE_FEATURE_DD_IBS_OBS && oc) {
+               w = full_write_or_warn(ofd, obuf, oc, outfile);
+               if (w < 0) goto out_status;
+               if (w > 0)
+                       G.out_part++;
+       }
+       if (close(ifd) < 0) {
+die_infile:
+               bb_perror_msg_and_die("%s", infile);
+       }
 
-    printf ("%ld+%d records in\n", (long)(intotal / blockSize),
-           (intotal % blockSize) != 0);
-    printf ("%ld+%d records out\n", (long)(outTotal / blockSize),
-           (outTotal % blockSize) != 0);
-    exit( TRUE);
-  usage:
+       if (close(ofd) < 0) {
+die_outfile:
+               bb_perror_msg_and_die("%s", outfile);
+       }
+out_status:
+       dd_output_status(0);
 
-    usage( dd_usage);
+       return EXIT_SUCCESS;
 }
-
-