forked from bonsai/harakit
		
	Merge pull request 'dj(1) - disk jockey' (#28) from dj into main
Reviewed-on: bonsai/coreutils#28
This commit is contained in:
		
						commit
						14fd23ddba
					
				@ -57,6 +57,9 @@ test: build
 | 
				
			|||||||
	tests/cc-compat.sh
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						tests/cc-compat.sh
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			||||||
	tests/posix-compat.sh
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						tests/posix-compat.sh
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			||||||
 | 
					
 | 
				
			||||||
 | 
					dj: src/dj.c build_dir
 | 
				
			||||||
 | 
						$(CC) $(CFLAGS) -o build/bin/dj src/dj.c
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			||||||
 | 
					
 | 
				
			||||||
false: src/false.rs build_dir
 | 
					false: src/false.rs build_dir
 | 
				
			||||||
	$(RUSTC) $(RUSTCFLAGS) -o build/bin/false src/false.rs
 | 
						$(RUSTC) $(RUSTCFLAGS) -o build/bin/false src/false.rs
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
				
			|||||||
							
								
								
									
										155
									
								
								docs/dj.1
									
									
									
									
									
										Normal file
									
								
							
							
						
						
									
										155
									
								
								docs/dj.1
									
									
									
									
									
										Normal file
									
								
							@ -0,0 +1,155 @@
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			|||||||
 | 
					.TH dj 1
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			||||||
 | 
					
 | 
				
			||||||
 | 
					.SH NAME
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			||||||
 | 
					
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			||||||
 | 
					dj \(en disk jockey
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			||||||
 | 
					
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			||||||
 | 
					.SH SYNOPSIS
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			||||||
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			||||||
 | 
					dj
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			||||||
 | 
					.RB ( -AdHnq )
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			||||||
 | 
					.RB ( -a
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			||||||
 | 
					.RB [ byte ])
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			||||||
 | 
					.RB ( -c
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			||||||
 | 
					.RB [ count ])
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					.RB ( -i
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			||||||
 | 
					.R [
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			||||||
 | 
					.B input file
 | 
				
			||||||
 | 
					.R ])
 | 
				
			||||||
 | 
					.RB ( -b
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			||||||
 | 
					.R [
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			||||||
 | 
					.B input block size
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			||||||
 | 
					.R ])
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			||||||
 | 
					.RB ( -s
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			||||||
 | 
					.R [
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			||||||
 | 
					.B input offset
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			||||||
 | 
					.R ])
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			||||||
 | 
					
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			||||||
 | 
					.RB ( -o
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			||||||
 | 
					.R [
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			||||||
 | 
					.B output file
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			||||||
 | 
					.R ])
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			||||||
 | 
					.RB ( -B
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			||||||
 | 
					.R [
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			||||||
 | 
					.B output block size
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			||||||
 | 
					.R ])
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			||||||
 | 
					.RB ( -S
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			||||||
 | 
					.R [
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			||||||
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					.B output offset
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			||||||
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					.R ])
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			||||||
 | 
					
 | 
				
			||||||
 | 
					.SH USAGE
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					The
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			||||||
 | 
					.B -i
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			||||||
 | 
					option takes a path as an argument to open and use in place of standard input.
 | 
				
			||||||
 | 
					The
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			||||||
 | 
					.B -o
 | 
				
			||||||
 | 
					option does the same in place of standard output. Dj does not truncate output
 | 
				
			||||||
 | 
					files and instead writes over the bytes in the existing file.
 | 
				
			||||||
 | 
					.PP
 | 
				
			||||||
 | 
					The
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			||||||
 | 
					.B -b
 | 
				
			||||||
 | 
					option takes a numeric argument as the size in bytes of the input buffer and
 | 
				
			||||||
 | 
					the
 | 
				
			||||||
 | 
					.B -B
 | 
				
			||||||
 | 
					option does the same for the output buffer, the default for both being 1024
 | 
				
			||||||
 | 
					bytes, or one kibibyte (KiB).
 | 
				
			||||||
 | 
					.PP
 | 
				
			||||||
 | 
					The
 | 
				
			||||||
 | 
					.B -s
 | 
				
			||||||
 | 
					option takes a numeric argument as the number of bytes to skip into the input
 | 
				
			||||||
 | 
					before starting to read, and the
 | 
				
			||||||
 | 
					.B -S
 | 
				
			||||||
 | 
					option skips a number of bytes through the output before starting to write from
 | 
				
			||||||
 | 
					the input. If the input is a stream the bytes are read and discarded. If the
 | 
				
			||||||
 | 
					output is a stream, nul characters are printed.
 | 
				
			||||||
 | 
					.PP
 | 
				
			||||||
 | 
					The
 | 
				
			||||||
 | 
					.B -a
 | 
				
			||||||
 | 
					option takes one argument of one byte in length and pads the input buffer with
 | 
				
			||||||
 | 
					that byte in the event that a read doesn't fill the input buffer, and the
 | 
				
			||||||
 | 
					.B -A
 | 
				
			||||||
 | 
					option takes no arguments and pads with nuls.
 | 
				
			||||||
 | 
					The
 | 
				
			||||||
 | 
					.B -c
 | 
				
			||||||
 | 
					option specifies an amount of reads to make, and if 0 (the default) dj will
 | 
				
			||||||
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					continue reading until a partial or empty read.
 | 
				
			||||||
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					.PP
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			||||||
 | 
					On a partial or empty read, dj prints a diagnostic message (unless the
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			||||||
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					.B -q
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			||||||
 | 
					option is specified) and exits (unless the
 | 
				
			||||||
 | 
					.B -n
 | 
				
			||||||
 | 
					option is specified, in which case only two consecutive empty reads will cause
 | 
				
			||||||
 | 
					dj to exit).
 | 
				
			||||||
 | 
					At exit, usage statistics are printed unless the option
 | 
				
			||||||
 | 
					.B -q
 | 
				
			||||||
 | 
					is specified a second time. The
 | 
				
			||||||
 | 
					.B -H
 | 
				
			||||||
 | 
					option will make these diagnostics human-readable.
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					.SH DIAGNOSTICS
 | 
				
			||||||
 | 
					
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			||||||
 | 
					The
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			||||||
 | 
					.B -d
 | 
				
			||||||
 | 
					option prints all information, user-specified or otherwise, before program
 | 
				
			||||||
 | 
					execution.
 | 
				
			||||||
 | 
					.PP
 | 
				
			||||||
 | 
					When dj exits, by default statistics are printed for input and output to
 | 
				
			||||||
 | 
					standard error in the following format:
 | 
				
			||||||
 | 
					.PP
 | 
				
			||||||
 | 
					.R {records read} {ASCII unit separator} {partial records read}
 | 
				
			||||||
 | 
					.R {ASCII record separator} {records written} {ASCII unit separator}
 | 
				
			||||||
 | 
					.R {partial records written} {ASCII group separator} {bytes read}
 | 
				
			||||||
 | 
					.R {ASCII record separator} {bytes written} {ASCII file separator}
 | 
				
			||||||
 | 
					.PP
 | 
				
			||||||
 | 
					If the
 | 
				
			||||||
 | 
					.B -H
 | 
				
			||||||
 | 
					option is specified dj instead uses this following format:
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			||||||
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					.PP
 | 
				
			||||||
 | 
					.R {records read} '+' {partial records read} '>' {records written}
 | 
				
			||||||
 | 
					.R '+' {partial records written} ';' {bytes read} '>' {bytes written}
 | 
				
			||||||
 | 
					.R {ASCII line feed}
 | 
				
			||||||
 | 
					.PP
 | 
				
			||||||
 | 
					The
 | 
				
			||||||
 | 
					.B -q
 | 
				
			||||||
 | 
					option suppresses error messages which print when a read or write is partial or
 | 
				
			||||||
 | 
					empty and when used twice suppresses diagnostic output entirely.
 | 
				
			||||||
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					.PP
 | 
				
			||||||
 | 
					In non-recoverable errors that don't pertain to dj's read-write cycle, a
 | 
				
			||||||
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					diagnostic message is printed and dj exits with the appropriate sysexits(3)
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			||||||
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					status.
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					.SH BUGS
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					If
 | 
				
			||||||
 | 
					.B -n
 | 
				
			||||||
 | 
					is specified along with a specified count, actual byte output may be lower than
 | 
				
			||||||
 | 
					expected (the product of the count multiplied by the input block size). If the
 | 
				
			||||||
 | 
					.B -a
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			||||||
 | 
					or
 | 
				
			||||||
 | 
					.B -A
 | 
				
			||||||
 | 
					options are used this could make data written nonsensical.
 | 
				
			||||||
 | 
					.PP
 | 
				
			||||||
 | 
					Many lowercase options have capitalized variants and vice-versa which can be
 | 
				
			||||||
 | 
					confusing. Capitalized options tend to affect output or are more intense
 | 
				
			||||||
 | 
					versions of lowercase options.
 | 
				
			||||||
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			||||||
 | 
					.SH RATIONALE
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			||||||
 | 
					
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			||||||
 | 
					Dj was modeled after the dd utility specified in POSIX but adds additional
 | 
				
			||||||
 | 
					features: typical option formatting, allowing seeks to be specified in bytes
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			||||||
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					rather than in blocks, allowing arbitrary bytes as padding, and printing in a
 | 
				
			||||||
 | 
					format that's easy to parse for machines. It also neglects character
 | 
				
			||||||
 | 
					conversion, which may be dd's original intent but is irrelevant to its modern
 | 
				
			||||||
 | 
					use.
 | 
				
			||||||
 | 
					
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			||||||
 | 
					.SH COPYRIGHT
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			||||||
 | 
					
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			||||||
 | 
					Copyright (C) 2023 DTB. License AGPLv3+: GNU AGPL version 3 or later
 | 
				
			||||||
 | 
					<https://gnu.org/licenses/agpl.html>.
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			||||||
 | 
					
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			||||||
 | 
					.SH SEE ALSO
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					dd(1)
 | 
				
			||||||
							
								
								
									
										434
									
								
								src/dj.c
									
									
									
									
									
										Normal file
									
								
							
							
						
						
									
										434
									
								
								src/dj.c
									
									
									
									
									
										Normal file
									
								
							@ -0,0 +1,434 @@
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			|||||||
 | 
					#include <ctype.h> /* isupper(3), tolower(3) */
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			||||||
 | 
					#include <errno.h> /* errno */
 | 
				
			||||||
 | 
					#include <fcntl.h> /* open(2) */
 | 
				
			||||||
 | 
					#include <stdio.h> /* fprintf(3), stderr */
 | 
				
			||||||
 | 
					#include <stdlib.h> /* free(3), malloc(3), strtol(3), size_t */
 | 
				
			||||||
 | 
					#include <string.h> /* memcpy(3), memmove(3), memset(3) */
 | 
				
			||||||
 | 
					#include <sysexits.h> /* EX_OK, EX_USAGE */
 | 
				
			||||||
 | 
					#include <unistd.h> /* close(2), getopt(3), lseek(2), read(2), write(2),
 | 
				
			||||||
 | 
					                       optarg, optind, STDIN_FILENO, STDOUT_FILENO */
 | 
				
			||||||
 | 
					extern int errno;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* dj uses two structures that respectively correspond to the reading and
 | 
				
			||||||
 | 
					 * writing ends of its jockeyed "pipe". User-configurable members are noted
 | 
				
			||||||
 | 
					 * with their relevant options. */
 | 
				
			||||||
 | 
					struct Io{
 | 
				
			||||||
 | 
						int bs;			/* buffer size (-bB) */
 | 
				
			||||||
 | 
						size_t bufuse;	/* buffer usage */
 | 
				
			||||||
 | 
						char *buf;		/* buffer */
 | 
				
			||||||
 | 
						int bytes;		/* bytes processed */
 | 
				
			||||||
 | 
						int fd;			/* file descriptor */
 | 
				
			||||||
 | 
						int fl;			/* file opening flags */
 | 
				
			||||||
 | 
						char *fn;		/* file name (may be stdin_name or stdout_name) (-io) */
 | 
				
			||||||
 | 
						int prec;		/* partial records processed */
 | 
				
			||||||
 | 
						int rec;		/* records processed */
 | 
				
			||||||
 | 
						long seek;		/* bytes to seek/skip (will be 0 after skippage) (-sS) */
 | 
				
			||||||
 | 
					} ep[2]; /* "engineered pipe"; also "extended play", for the deejay */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Additionally, the following global variables are used to store user options.
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* (-a)  */ static int align; /* Only the lower 8b are used but align is
 | 
				
			||||||
 | 
					                               * negative if no alignment is being done. */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* (-c)  */ static int count; /* 0 if dj(1) runs until no more reads are
 | 
				
			||||||
 | 
					                               * possible. */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* ASCII field separator delimited statistics */
 | 
				
			||||||
 | 
					            static char *fmt_asv   = "%d\037%d\036%d\037%d\035%d\036%d\034";
 | 
				
			||||||
 | 
					/* human-readable statistics */
 | 
				
			||||||
 | 
					            static char *fmt_human = "%d+%d > %d+%d; %d > %d\n";
 | 
				
			||||||
 | 
					/* pointer to chosen formatting */
 | 
				
			||||||
 | 
					/* (-H)  */ static char *fmt_output; /* fmt_asv (default) or fmt_human (-H) */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* (-dq) */ static char debug;       /*
 | 
				
			||||||
 | 
					 *  -d  increments             dj -qq | 0 - no diagnostic output whatsoever
 | 
				
			||||||
 | 
					 *   -q decrements             dj -q  | 1 - typical output without
 | 
				
			||||||
 | 
					 *                                    |     notifications on partial reads or
 | 
				
			||||||
 | 
					 *                                    |     writes
 | 
				
			||||||
 | 
					 *                             dj     | 2 - typical output (default)
 | 
				
			||||||
 | 
					 *                             dj -d  | 3 - verbose status messages */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* (-n)  */ static char noerror;     /* 0 - exits on partial reads or writes
 | 
				
			||||||
 | 
					                                      *     (default)
 | 
				
			||||||
 | 
					                                      * 1 - retries on partial reads/writes
 | 
				
			||||||
 | 
					                                      *     (-f) */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Non-configurable defaults. */
 | 
				
			||||||
 | 
					#define bs_default 1024 /* GNU dd(1) default; twice POSIX but a neat 2^10 */
 | 
				
			||||||
 | 
					static char *program_name = "<no argv[0]>";
 | 
				
			||||||
 | 
					static char *stdin_name = "<stdin>";
 | 
				
			||||||
 | 
					static char *stdout_name = "<stdout>";
 | 
				
			||||||
 | 
					static int read_flags = O_RDONLY; /* These flags are consistent with Busybox */
 | 
				
			||||||
 | 
					static int write_flags = O_WRONLY | O_CREAT; /* dd(1). */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Macro to set defaults for user-configurable options. */
 | 
				
			||||||
 | 
					#define setdefaults do{ \
 | 
				
			||||||
 | 
						align = -1; \
 | 
				
			||||||
 | 
						count = 0; \
 | 
				
			||||||
 | 
						debug = 2; \
 | 
				
			||||||
 | 
						fmt_output = fmt_asv; \
 | 
				
			||||||
 | 
						noerror = 0; \
 | 
				
			||||||
 | 
						ep[0].fl = read_flags; \
 | 
				
			||||||
 | 
						Io_setdefaults(&ep[0]); \
 | 
				
			||||||
 | 
						ep[1].fl = write_flags; \
 | 
				
			||||||
 | 
						Io_setdefaults(&ep[1]); }while(0)
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					#define MIN(a, b) (((a) < (b)) ? (a) : (b))
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Macro to check if fd is a std* file, e.g. stdin. */
 | 
				
			||||||
 | 
					#define fdisstd(fd) \
 | 
				
			||||||
 | 
							((fd) == STDIN_FILENO \
 | 
				
			||||||
 | 
							|| (fd) == STDOUT_FILENO \
 | 
				
			||||||
 | 
							|| (fd) == STDERR_FILENO)
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Macro to call the cleanup functions that operate on struct io on the
 | 
				
			||||||
 | 
					 * particular io[2] used in main. Error conditions are not checked because this
 | 
				
			||||||
 | 
					 * is only used when the program is about to terminate (hence its name). */
 | 
				
			||||||
 | 
					#define terminate(io) do{ \
 | 
				
			||||||
 | 
						Io_buffree(&(io)[0]); \
 | 
				
			||||||
 | 
						Io_buffree(&(io)[1]); \
 | 
				
			||||||
 | 
						Io_fdclose(&(io)[0]); \
 | 
				
			||||||
 | 
						Io_fdclose(&(io)[1]); }while(0)
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Allocates *io's buffer. Returns NULL if unsuccessful. */
 | 
				
			||||||
 | 
					static void *
 | 
				
			||||||
 | 
					Io_bufalloc(struct Io *io){
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return (io->buf = malloc(io->bs * (sizeof *io->buf)));
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Frees *io's buffer. Returns io. */
 | 
				
			||||||
 | 
					static struct Io *
 | 
				
			||||||
 | 
					Io_buffree(struct Io *io){
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						free(io->buf);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return io;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Fills the unused portion of io's buffer with padding, updating io->bufuse.
 | 
				
			||||||
 | 
					 * Returns io. */
 | 
				
			||||||
 | 
					static struct Io *
 | 
				
			||||||
 | 
					Io_bufrpad(struct Io *io, int padding){
 | 
				
			||||||
 | 
						
 | 
				
			||||||
 | 
						memset(io->buf + io->bufuse, padding, io->bs - io->bufuse);
 | 
				
			||||||
 | 
						io->bufuse = io->bs;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return io;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Copies from the buffer in src as much as possible to the free space in the
 | 
				
			||||||
 | 
					 * dest buffer, removing the copied units from src and permuting the remaining
 | 
				
			||||||
 | 
					 * units in the src buffer to the start of the buffer, modifying both the src
 | 
				
			||||||
 | 
					 * and dest bufuse and returning dest. */
 | 
				
			||||||
 | 
					static struct Io*
 | 
				
			||||||
 | 
					Io_bufxapp(struct Io *dest, struct Io *src){
 | 
				
			||||||
 | 
						int n;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						n = MIN(src->bufuse, dest->bs - dest->bufuse);
 | 
				
			||||||
 | 
						memcpy(dest->buf + dest->bufuse, src->buf, n);
 | 
				
			||||||
 | 
						dest->bufuse += n;
 | 
				
			||||||
 | 
						memmove(src->buf, src->buf + n, src->bs - n);
 | 
				
			||||||
 | 
						src->bufuse -= n;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return dest;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Copies from the buffer in src to the buffer in dest no more than n units,
 | 
				
			||||||
 | 
					 * removing the copied units from src and permuting the remaining units in the
 | 
				
			||||||
 | 
					 * src buffer to the start of the buffer, modifying both the src and dest
 | 
				
			||||||
 | 
					 * bufuse and returning dest. */
 | 
				
			||||||
 | 
					static struct Io*
 | 
				
			||||||
 | 
					Io_bufxfer(struct Io *dest, struct Io *src, int n){
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						memcpy(dest->buf, src->buf, (dest->bufuse = n));
 | 
				
			||||||
 | 
						memmove(src->buf, src->buf + n, (src->bufuse -= n));
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return dest;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Closes io->fn and returns -1 on error, otherwise io->fd. */
 | 
				
			||||||
 | 
					static int
 | 
				
			||||||
 | 
					Io_fdclose(struct Io *io){
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return fdisstd(io->fd)
 | 
				
			||||||
 | 
							? 0
 | 
				
			||||||
 | 
							: close(io->fd);
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Opens io->fn and saves the file descriptor into io->fd. Returns io->fd,
 | 
				
			||||||
 | 
					 * which will be -1 if an error occured. */
 | 
				
			||||||
 | 
					static int
 | 
				
			||||||
 | 
					Io_fdopen(struct Io *io, char *fn){
 | 
				
			||||||
 | 
						int fd;
 | 
				
			||||||
 | 
						
 | 
				
			||||||
 | 
						if((fd = open(fn, io->fl,
 | 
				
			||||||
 | 
										/* these are the flags used by touch(1p) */
 | 
				
			||||||
 | 
										S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH))
 | 
				
			||||||
 | 
									!= -1
 | 
				
			||||||
 | 
								&& Io_fdclose(io) == 0){
 | 
				
			||||||
 | 
							io->fd = fd;
 | 
				
			||||||
 | 
							io->fn = fn;
 | 
				
			||||||
 | 
						}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return fd;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Seeks io->seek bytes through *io's file descriptor, (counter-intuitively)
 | 
				
			||||||
 | 
					 * returning -1 if successful and a sysexits.h exit code if an unrecoverable
 | 
				
			||||||
 | 
					 * error occurred. io->buf will be cleared of useful bytes and io->seek will
 | 
				
			||||||
 | 
					 * be set to zero to indicate the seek occurred. */
 | 
				
			||||||
 | 
					static int
 | 
				
			||||||
 | 
					Io_fdseek(struct Io *io){
 | 
				
			||||||
 | 
						int (*op)(int, void *, size_t);
 | 
				
			||||||
 | 
						
 | 
				
			||||||
 | 
						if(!fdisstd(io->fd) && lseek(io->fd, io->seek, SEEK_SET) != -1)
 | 
				
			||||||
 | 
							return -1;
 | 
				
			||||||
 | 
						else if(io->fl == write_flags){
 | 
				
			||||||
 | 
							memset(io->buf, '\0', io->bs);
 | 
				
			||||||
 | 
							/* This is a dirty trick; rather than testing conditions and operating
 | 
				
			||||||
 | 
							 * likewise, because the parameters to read or write are going to be
 | 
				
			||||||
 | 
							 * the same either way, just use a function pointer to keep track of
 | 
				
			||||||
 | 
							 * the intended operation. */
 | 
				
			||||||
 | 
							op = (int (*)(int, void *, size_t))&write;
 | 
				
			||||||
 | 
							/* Function pointer casts are risky; this works because the difference
 | 
				
			||||||
 | 
							 * is in the second parameter and only that write(2) makes the buffer
 | 
				
			||||||
 | 
							 * const whereas read(2) does not. To avoid even the slightest
 | 
				
			||||||
 | 
							 * undefined behavior comment out the cast, just be ready for a
 | 
				
			||||||
 | 
							 * -Wincompatible-function-pointer-types if your compiler notices it.
 | 
				
			||||||
 | 
							 */
 | 
				
			||||||
 | 
						}else
 | 
				
			||||||
 | 
							op = &read;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* We're going to cheat and use bufuse as the retval for write(2), which is
 | 
				
			||||||
 | 
						 * fine because it'll be zeroed as this function returns anyway. */
 | 
				
			||||||
 | 
						do{	if(	(io->bufuse = (*op)(io->fd, io->buf, MIN(io->bs, io->seek))) == 0)
 | 
				
			||||||
 | 
								/* second chance */
 | 
				
			||||||
 | 
								io->bufuse = (*op)(io->fd, io->buf, MIN(io->bs, io->seek));
 | 
				
			||||||
 | 
						}while((io->seek -= io->bufuse) > 0 && io->bufuse != 0);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						io->bufuse = 0;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return -1;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Reads io->bs bytes from *io's file descriptor into io->buf, storing the
 | 
				
			||||||
 | 
					 * number of read bytes in io->bufuse and updating io->bytes. If io->bufuse is
 | 
				
			||||||
 | 
					 * 0, errno will probably be set. Returns io. */
 | 
				
			||||||
 | 
					static struct Io *
 | 
				
			||||||
 | 
					Io_read(struct Io *io){
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						io->bytes += (io->bufuse = read(io->fd, io->buf, io->bs));
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return io;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Sets the variables in a struct *io to the defaults. Identifies the read/
 | 
				
			||||||
 | 
					 * write ends of the "pipe" by checking io->fl. Returns io. */
 | 
				
			||||||
 | 
					static struct Io *
 | 
				
			||||||
 | 
					Io_setdefaults(struct Io *io){
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						io->bs = bs_default;
 | 
				
			||||||
 | 
						io->buf = NULL;
 | 
				
			||||||
 | 
						io->bytes = 0;
 | 
				
			||||||
 | 
						io->fd = (io->fl == read_flags) ? STDIN_FILENO : STDOUT_FILENO;
 | 
				
			||||||
 | 
						io->fn = (io->fl == read_flags) ? stdin_name   : stdout_name;
 | 
				
			||||||
 | 
						io->prec = 0;
 | 
				
			||||||
 | 
						io->rec = 0;
 | 
				
			||||||
 | 
						io->seek = 0;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return io;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Writes io->bufuse units from io->buf to io->fd, permuting any unwritten
 | 
				
			||||||
 | 
					 * bytes to the start of io->buf and updating io->bufuse. If io->bufuse doesn't
 | 
				
			||||||
 | 
					 * change, errno will probably be set. Returns io. */
 | 
				
			||||||
 | 
					static struct Io *
 | 
				
			||||||
 | 
					Io_write(struct Io *io){
 | 
				
			||||||
 | 
						int t;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						if((t = write(io->fd, io->buf, io->bufuse)) > 0)
 | 
				
			||||||
 | 
							memmove(io->buf, io->buf + t, (io->bufuse -= t));
 | 
				
			||||||
 | 
						io->bytes += t;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return io;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Prints an error message suitable for the event of an operating system error,
 | 
				
			||||||
 | 
					 * with the error itself to be described in the string s. */
 | 
				
			||||||
 | 
					static int
 | 
				
			||||||
 | 
					oserr(char *s){
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						fprintf(stderr, "%s: %s: %s\n", program_name, s, strerror(errno));
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return EX_OSERR;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Prints statistics regarding the use of dj, particularly partially and
 | 
				
			||||||
 | 
					 * completely read and written records, accessing debug, ep, and fmt_output. */
 | 
				
			||||||
 | 
					static void
 | 
				
			||||||
 | 
					output(void){
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						if(debug >= 1)
 | 
				
			||||||
 | 
							fprintf(stderr, fmt_output,
 | 
				
			||||||
 | 
								ep[0].rec, ep[0].prec, ep[1].rec, ep[1].prec,
 | 
				
			||||||
 | 
								ep[0].bytes, ep[1].bytes);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Parses the string s to an integer, returning either the integer or in the
 | 
				
			||||||
 | 
					 * case of an error a negative integer. This is used for argument parsing
 | 
				
			||||||
 | 
					 * (e.g. -B [int]) in dj and no negative integer would be valid anyway. */
 | 
				
			||||||
 | 
					static long
 | 
				
			||||||
 | 
					parse(char *s){
 | 
				
			||||||
 | 
						long r;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						errno = 0;
 | 
				
			||||||
 | 
						r = strtol(s, &s, 0);
 | 
				
			||||||
 | 
						return (*s == '\0' /* no chars left unparsed */ && errno == 0)
 | 
				
			||||||
 | 
							? r
 | 
				
			||||||
 | 
							: -1;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					static int
 | 
				
			||||||
 | 
					usage(void){
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						fprintf(stderr, "Usage: %s (-AdfHqQ) (-a [byte]) (-c [count])\n"
 | 
				
			||||||
 | 
							"\t(-i [input file]) (-b [input block size]) (-s [input offset])\n"
 | 
				
			||||||
 | 
							"\t(-o [output file]) (-B [output block size]) (-S [output offset])\n",
 | 
				
			||||||
 | 
							program_name);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return EX_USAGE;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					int main(int argc, char *argv[]){
 | 
				
			||||||
 | 
						int c;
 | 
				
			||||||
 | 
						int i;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						setdefaults;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						if(argc > 0){
 | 
				
			||||||
 | 
							program_name = argv[0];
 | 
				
			||||||
 | 
							while((c = getopt(argc, argv, "a:Ab:B:c:di:fhHqs:S:o:")) != -1)
 | 
				
			||||||
 | 
								switch(c){
 | 
				
			||||||
 | 
								case 'i': case 'o':
 | 
				
			||||||
 | 
									i = (c == 'o');
 | 
				
			||||||
 | 
									if(optarg[0] == '-' && optarg[1] == '\0'){ /* optarg == "-" */
 | 
				
			||||||
 | 
										ep[i].fd = (i == 0) ? STDIN_FILENO : STDOUT_FILENO;
 | 
				
			||||||
 | 
										ep[i].fn = (i == 0) ? stdin_name   : stdout_name;
 | 
				
			||||||
 | 
										break;
 | 
				
			||||||
 | 
									}else if(Io_fdopen(&ep[i], optarg) != -1)
 | 
				
			||||||
 | 
										break;
 | 
				
			||||||
 | 
									terminate(ep);
 | 
				
			||||||
 | 
									return oserr(optarg);
 | 
				
			||||||
 | 
								case 'A': align = '\0'; break;
 | 
				
			||||||
 | 
								case 'd': ++debug; break;
 | 
				
			||||||
 | 
								case 'n': noerror = 1; break;
 | 
				
			||||||
 | 
								case 'H': fmt_output = fmt_human; break;
 | 
				
			||||||
 | 
								case 'q': --debug; break;
 | 
				
			||||||
 | 
								case 'a':
 | 
				
			||||||
 | 
									if(optarg[0] != '\0' && optarg[1] == '\0'){
 | 
				
			||||||
 | 
										align = optarg[0];
 | 
				
			||||||
 | 
										break;
 | 
				
			||||||
 | 
									}
 | 
				
			||||||
 | 
									/* FALLTHROUGH */
 | 
				
			||||||
 | 
								case 'c': case 'b': case 's': case 'B': case 'S':
 | 
				
			||||||
 | 
									if(c == 'c' && (count = parse(optarg)) >= 0)
 | 
				
			||||||
 | 
										break;
 | 
				
			||||||
 | 
									i = isupper(c);
 | 
				
			||||||
 | 
									c = tolower(c);
 | 
				
			||||||
 | 
									if((c == 'b' && (ep[i].bs = parse(optarg)) > 0)
 | 
				
			||||||
 | 
											|| (c == 's' && (ep[i].seek = parse(optarg)) >= 0))
 | 
				
			||||||
 | 
										break;
 | 
				
			||||||
 | 
									/* FALLTHROUGH */
 | 
				
			||||||
 | 
								default:
 | 
				
			||||||
 | 
									terminate(ep);
 | 
				
			||||||
 | 
									return usage();
 | 
				
			||||||
 | 
								}
 | 
				
			||||||
 | 
						}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						if(debug >= 3)
 | 
				
			||||||
 | 
							fprintf(stderr,
 | 
				
			||||||
 | 
								"argv0=%s\n"
 | 
				
			||||||
 | 
								"in=%s\tibs=%d\tskip=%ld\talign=%hhx\tcount=%d\n"
 | 
				
			||||||
 | 
								"out=%s\tobs=%d\tseek=%ld\tdebug=%2d\tnoerror=%d\n",
 | 
				
			||||||
 | 
								program_name,
 | 
				
			||||||
 | 
								ep[0].fn, ep[0].bs, ep[0].seek, align, count,
 | 
				
			||||||
 | 
								ep[1].fn, ep[1].bs, ep[1].seek, debug, noerror);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						if(argc > optind){
 | 
				
			||||||
 | 
							terminate(ep);
 | 
				
			||||||
 | 
							return usage();
 | 
				
			||||||
 | 
						}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						for(i = 0; i <= 1; ++i){
 | 
				
			||||||
 | 
							if(Io_bufalloc(&ep[i]) == NULL){
 | 
				
			||||||
 | 
								fprintf(stderr, "%s: Failed to allocate %d bytes\n",
 | 
				
			||||||
 | 
									program_name, ep[i].bs);
 | 
				
			||||||
 | 
								terminate(ep);
 | 
				
			||||||
 | 
								return EX_OSERR;
 | 
				
			||||||
 | 
							}else if(ep[i].seek > 0)
 | 
				
			||||||
 | 
								switch(Io_fdseek(&ep[i])){
 | 
				
			||||||
 | 
								case EX_OK:
 | 
				
			||||||
 | 
									output();
 | 
				
			||||||
 | 
									terminate(ep);
 | 
				
			||||||
 | 
									return EX_OK;
 | 
				
			||||||
 | 
								}
 | 
				
			||||||
 | 
						}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						do{	/* read */
 | 
				
			||||||
 | 
							Io_read(&ep[0]);
 | 
				
			||||||
 | 
							if(!noerror && ep[0].bufuse == 0)
 | 
				
			||||||
 | 
								Io_read(&ep[0]); /* second chance */
 | 
				
			||||||
 | 
							if(ep[0].bufuse == 0) /* that's all she wrote */
 | 
				
			||||||
 | 
								break;
 | 
				
			||||||
 | 
							else if(ep[0].bufuse < ep[0].bs){
 | 
				
			||||||
 | 
								++ep[0].prec;
 | 
				
			||||||
 | 
								if(debug >= 2){
 | 
				
			||||||
 | 
									fprintf(stderr, "%s: Partial read:\n\t", program_name);
 | 
				
			||||||
 | 
									output();
 | 
				
			||||||
 | 
								}
 | 
				
			||||||
 | 
								if(!noerror)
 | 
				
			||||||
 | 
									count = 1;
 | 
				
			||||||
 | 
								if(align >= 0)
 | 
				
			||||||
 | 
									Io_bufrpad(&ep[0], align);
 | 
				
			||||||
 | 
							}else
 | 
				
			||||||
 | 
								++ep[0].rec;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
							/* write */
 | 
				
			||||||
 | 
							do{	if(ep[1].bs > ep[0].bs){ /* io[1].bs > io[0].bs */
 | 
				
			||||||
 | 
									Io_bufxapp(&ep[1], &ep[0]);
 | 
				
			||||||
 | 
									if(ep[0].bs + ep[1].bufuse <= ep[1].bs && count != 1)
 | 
				
			||||||
 | 
										continue; /* we could write more */
 | 
				
			||||||
 | 
								}else
 | 
				
			||||||
 | 
									Io_bufxfer(&ep[1], &ep[0], MIN(ep[0].bufuse, ep[1].bs));
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
								c = ep[1].bufuse;
 | 
				
			||||||
 | 
								Io_write(&ep[1]);
 | 
				
			||||||
 | 
								if(!noerror && ep[1].bufuse == c)
 | 
				
			||||||
 | 
									Io_write(&ep[1]); /* second chance */
 | 
				
			||||||
 | 
								if(c == ep[1].bufuse){ /* no more love */
 | 
				
			||||||
 | 
									count = 1;
 | 
				
			||||||
 | 
									break;
 | 
				
			||||||
 | 
								}else if(c > ep[1].bufuse && ep[1].bufuse > 0){
 | 
				
			||||||
 | 
									ep[1].prec += 1;
 | 
				
			||||||
 | 
									if(debug >= 2){
 | 
				
			||||||
 | 
										fprintf(stderr, "%s: Partial write:\n\t", program_name);
 | 
				
			||||||
 | 
										output();
 | 
				
			||||||
 | 
									}
 | 
				
			||||||
 | 
									if(!noerror)
 | 
				
			||||||
 | 
										count = 1;
 | 
				
			||||||
 | 
								}else if(ep[1].bufuse == 0 && c < ep[1].bs)
 | 
				
			||||||
 | 
									++ep[1].prec;
 | 
				
			||||||
 | 
								else
 | 
				
			||||||
 | 
									++ep[1].rec;
 | 
				
			||||||
 | 
							}while(ep[0].bufuse > 0);
 | 
				
			||||||
 | 
						}while(count == 0 || --count > 0);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						output();
 | 
				
			||||||
 | 
						terminate(ep);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return EX_OK;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
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		Reference in New Issue
	
	Block a user