diff options
| -rw-r--r-- | coreutils/dd.c | 78 | ||||
| -rw-r--r-- | docs/posix_conformance.txt | 1 |
2 files changed, 52 insertions, 27 deletions
diff --git a/coreutils/dd.c b/coreutils/dd.c index 6a5288da1..0c0ea07b9 100644 --- a/coreutils/dd.c +++ b/coreutils/dd.c @@ -55,7 +55,7 @@ //usage:#define dd_trivial_usage //usage: "[if=FILE] [of=FILE] " IF_FEATURE_DD_IBS_OBS("[ibs=N] [obs=N] ") "[bs=N] [count=N] [skip=N]\n" -//usage: " [seek=N]" IF_FEATURE_DD_IBS_OBS(" [conv=notrunc|noerror|sync|fsync]") +//usage: " [seek=N]" IF_FEATURE_DD_IBS_OBS(" [conv=notrunc|noerror|sync|fsync] [iflag=skip_bytes]") //usage:#define dd_full_usage "\n\n" //usage: "Copy a file with converting and formatting\n" //usage: "\n if=FILE Read from FILE instead of stdin" @@ -76,6 +76,7 @@ //usage: "\n conv=sync Pad blocks with zeros" //usage: "\n conv=fsync Physically write data out before finishing" //usage: "\n conv=swab Swap every pair of bytes" +//usage: "\n iflag=skip_bytes skip=N is in bytes" //usage: ) //usage: IF_FEATURE_DD_STATUS( //usage: "\n status=noxfer Suppress rate output" @@ -122,11 +123,15 @@ enum { FLAG_FSYNC = (1 << 3) * ENABLE_FEATURE_DD_IBS_OBS, FLAG_SWAB = (1 << 4) * ENABLE_FEATURE_DD_IBS_OBS, /* end of conv flags */ - FLAG_TWOBUFS = (1 << 5) * ENABLE_FEATURE_DD_IBS_OBS, - FLAG_COUNT = 1 << 6, - FLAG_STATUS = 1 << 7, - FLAG_STATUS_NONE = 1 << 7, - FLAG_STATUS_NOXFER = 1 << 8, + /* start of input flags */ + FLAG_IFLAG_SHIFT = 5, + FLAG_SKIP_BYTES = (1 << 5) * ENABLE_FEATURE_DD_IBS_OBS, + /* end of input flags */ + FLAG_TWOBUFS = (1 << 6) * ENABLE_FEATURE_DD_IBS_OBS, + FLAG_COUNT = 1 << 7, + FLAG_STATUS = 1 << 8, + FLAG_STATUS_NONE = 1 << 9, + FLAG_STATUS_NOXFER = 1 << 10, }; static void dd_output_status(int UNUSED_PARAM cur_signal) @@ -203,18 +208,47 @@ static bool write_and_stats(const void *buf, size_t len, size_t obs, # define XATOU_SFX xatoul_sfx #endif +#if ENABLE_FEATURE_DD_IBS_OBS +static int parse_comma_flags(char *val, const char *words, const char *error_in) +{ + int flags = 0; + while (1) { + int n; + char *arg; + /* find ',', replace them with NUL so we can use val for + * index_in_strings() without copying. + * We rely on val being non-null, else strchr would fault. + */ + arg = strchr(val, ','); + if (arg) + *arg = '\0'; + n = index_in_strings(words, val); + if (n < 0) + bb_error_msg_and_die(bb_msg_invalid_arg_to, val, error_in); + flags |= (1 << n); + if (!arg) /* no ',' left, so this was the last specifier */ + break; + *arg = ','; /* to preserve ps listing */ + val = arg + 1; /* skip this keyword and ',' */ + } + return flags; +} +#endif + int dd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int dd_main(int argc UNUSED_PARAM, char **argv) { static const char keywords[] ALIGN1 = "bs\0""count\0""seek\0""skip\0""if\0""of\0"IF_FEATURE_DD_STATUS("status\0") #if ENABLE_FEATURE_DD_IBS_OBS - "ibs\0""obs\0""conv\0" + "ibs\0""obs\0""conv\0""iflag\0" #endif ; #if ENABLE_FEATURE_DD_IBS_OBS static const char conv_words[] ALIGN1 = "notrunc\0""sync\0""noerror\0""fsync\0""swab\0"; + static const char iflag_words[] ALIGN1 = + "skip_bytes\0"; #endif #if ENABLE_FEATURE_DD_STATUS static const char status_words[] ALIGN1 = @@ -232,6 +266,7 @@ int dd_main(int argc UNUSED_PARAM, char **argv) OP_ibs, OP_obs, OP_conv, + OP_iflag, /* Must be in the same order as FLAG_XXX! */ OP_conv_notrunc = 0, OP_conv_sync, @@ -251,6 +286,7 @@ int dd_main(int argc UNUSED_PARAM, char **argv) //ibm from ASCII to alternate EBCDIC /* Partially implemented: */ //swab swap every pair of input bytes: will abort on non-even reads + OP_iflag_skip_bytes, #endif }; smallint exitcode = EXIT_FAILURE; @@ -315,24 +351,11 @@ int dd_main(int argc UNUSED_PARAM, char **argv) /*continue;*/ } if (what == OP_conv) { - while (1) { - int n; - /* find ',', replace them with NUL so we can use val for - * index_in_strings() without copying. - * We rely on val being non-null, else strchr would fault. - */ - arg = strchr(val, ','); - if (arg) - *arg = '\0'; - n = index_in_strings(conv_words, val); - if (n < 0) - bb_error_msg_and_die(bb_msg_invalid_arg_to, val, "conv"); - G.flags |= (1 << n); - if (!arg) /* no ',' left, so this was the last specifier */ - break; - /* *arg = ','; - to preserve ps listing? */ - val = arg + 1; /* skip this keyword and ',' */ - } + G.flags |= parse_comma_flags(val, conv_words, "conv"); + /*continue;*/ + } + if (what == OP_iflag) { + G.flags |= parse_comma_flags(val, iflag_words, "iflag") << FLAG_IFLAG_SHIFT; /*continue;*/ } #endif @@ -421,9 +444,10 @@ int dd_main(int argc UNUSED_PARAM, char **argv) outfile = bb_msg_standard_output; } if (skip) { - if (lseek(ifd, skip * ibs, SEEK_CUR) < 0) { + size_t blocksz = (G.flags & FLAG_SKIP_BYTES) ? 1 : ibs; + if (lseek(ifd, skip * blocksz, SEEK_CUR) < 0) { do { - ssize_t n = safe_read(ifd, ibuf, ibs); + ssize_t n = safe_read(ifd, ibuf, blocksz); if (n < 0) goto die_infile; if (n == 0) diff --git a/docs/posix_conformance.txt b/docs/posix_conformance.txt index 5b616d701..c0582dc23 100644 --- a/docs/posix_conformance.txt +++ b/docs/posix_conformance.txt @@ -178,6 +178,7 @@ dd POSIX options: conv=noerror | yes | | conv=notrunc | yes | | conv=sync | yes | | + iflag=skip_bytes| yes | | dd Busybox specific options: conv=fsync |