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od: support multiple input files (#463)
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* od: support multiple input files

* Standards document specifies multiple input files should be processed [1]
* Follow BSD od and don't treat '-' argument specially; read stdin only if no arguments are given
* Update usage string
* Options -N and -j affect the input stream overall, not just the 1st file processed
* Uneven input data left over at EOF is combined with input from the next file
* Uneven input data at end of the last file gets its own dump_line() call
* Formatting routines are now written without the need for global $pffmt
* test1: "echo hello |  perl od -c -N 2" --> format 1st two bytes from stdin as characters
* test2: "od -j 1 -x  awk ar" --> dump awk and ar files as hex, skipping 1st byte of input

1. https://pubs.opengroup.org/onlinepubs/009696899/utilities/od.html

* kill extra return statement

* emit_offset() conditionally prints newline or space
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@mknos
mknos committed Mar 3, 2024
1 parent b45269d commit 081ff04
Showing 1 changed file with 99 additions and 82 deletions.
181 changes: 99 additions & 82 deletions bin/od
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Expand Up @@ -25,8 +25,8 @@ use constant PRINTMAX => 126;
use vars qw/ $opt_A $opt_b $opt_c $opt_d $opt_f $opt_i $opt_j $opt_l $opt_N
$opt_o $opt_v $opt_x /;

my ($offset1, $radix, $data, @arr, $len, $fh, $lim);
my ($lastline, $pffmt, $strfmt, $ml);
my ($offset1, $radix, $data, @arr, $len, $lim);
my ($lastline, $strfmt, $ml);

my %charescs = (
0 => ' \0',
Expand Down Expand Up @@ -64,7 +64,6 @@ if (defined $opt_j) {
warn "$Program: bad argument to -j: '$opt_j'\n";
exit EX_FAILURE;
}
$offset1 = $opt_j;
}
if (defined $opt_N) {
if ($opt_N =~ m/\D/) {
Expand All @@ -74,37 +73,6 @@ if (defined $opt_N) {
$lim = $opt_N;
}

if (defined $ARGV[0] && $ARGV[0] ne '-') {
unless (open $fh, '<', $ARGV[0]) {
warn "$Program: cannot open '$ARGV[0]': $!\n";
exit EX_FAILURE;
}
}
else {
$fh = *STDIN;
}

binmode $fh;
if ($offset1) {
foreach (1 .. $offset1) {
$len = read $fh, $data, 1;
if ($len == 0) {
warn "$Program: cannot skip past end of input\n";
exit EX_FAILURE;
}
unless (defined $len) {
warn "$Program: read error: $!\n";
exit EX_FAILURE;
}
undef $data;
}
}
if (defined($lim) && $lim == 0) {
printf("%.8$radix\n", $offset1) if $radix;
close $fh;
exit EX_SUCCESS;
}

my $fmt;
if ($opt_b) {
$fmt = \&octal1;
Expand Down Expand Up @@ -134,49 +102,103 @@ else {
$fmt = \&octal2;
}

my $buf;
my $nread = 0;
while ($len = read($fh, $buf, 1)) {
$data .= $buf;
$nread++;

my $is_limit = defined($lim) && $nread == $lim;
if (length($data) == LINESZ || $is_limit || eof($fh)) {
$ml = ''; # multi-line indention
if (&diffdata || $opt_v) {
printf("%.8$radix ", $offset1) if $radix;
&$fmt;
printf("%s$strfmt\n", $ml, @arr);
$ml = ' ' x 9;
}
else {
print "*\n";
}
$lastline = $data . '|';
$offset1 += length $data;
undef $data;
my $rc = EX_SUCCESS;
foreach my $file (@ARGV) {
if (-d $file) {
warn "$Program: '$file' is a directory\n";
$rc = EX_FAILURE;
next;
}
last if $is_limit;
my $fh;
unless (open $fh, '<', $file) {
warn "$Program: cannot open '$file': $!\n";
$rc = EX_FAILURE;
next;
}
binmode $fh;

do_skip($fh) if $opt_j;
dump_file($fh);
close $fh;
}
unless (defined $len) {
warn "$Program: read error: $!\n";
exit EX_FAILURE;
unless (@ARGV) {
do_skip(*STDIN) if $opt_j;
dump_file(*STDIN);
}
dump_line() if (defined $data);
emit_offset(1);
exit $rc;

printf("%.8$radix\n", $offset1) if $radix;
close $fh;
exit EX_SUCCESS;
sub limit_reached {
return defined($lim) && $nread >= $lim;
}

sub emit_offset {
my $nl = shift;
return unless $radix;
printf "%.8$radix%s", $offset1, $nl ? "\n" : ' ';
}

sub dump_line {
$ml = ''; # multi-line indention
if (&diffdata || $opt_v) {
emit_offset();
&$fmt;
printf("%s$strfmt\n", $ml, @arr);
$ml = ' ' x 9;
}
else {
print "*\n";
}
$lastline = $data . '|';
$offset1 += length $data;
undef $data;
}

sub dump_file {
my $fh = shift;
my $buf;

while (!limit_reached() && !eof($fh)) {
$len = read $fh, $buf, 1;
unless (defined $len) {
warn "$Program: read error: $!\n";
$rc = EX_FAILURE;
return;
}
$data .= $buf;
$nread++;

dump_line() if (length($data) == LINESZ);
}
}

sub do_skip {
my $fh = shift;
my $buf;

while ($opt_j > 0) {
$len = read $fh, $buf, 1;
if ($len == 0) {
warn "$Program: skip past end of input\n";
exit EX_FAILURE;
}
unless (defined $len) {
warn "$Program: read error: $!\n";
exit EX_FAILURE;
}
$opt_j--;
$offset1++;
}
}

sub octal1 {
$pffmt = '%.3o ';
@arr = unpack 'C*', $data;
$strfmt = $pffmt x (scalar @arr);
$strfmt = '%.3o ' x (scalar @arr);
}

sub char1 {
$pffmt = '%s';
$strfmt = $pffmt;

@arr = ();
my @arr1 = unpack 'C*', $data;
for my $val (@arr1) {
Expand All @@ -190,6 +212,7 @@ sub char1 {
$arr[0] .= " " . chr($val) . " ";
}
}
$strfmt = '%s';
}

sub udecimal {
Expand All @@ -199,8 +222,7 @@ sub udecimal {
else {
@arr = unpack 'S*', $data;
}
$pffmt = '%5u ';
$strfmt = $pffmt x (scalar @arr);
$strfmt = '%5u ' x (scalar @arr);
}

sub float {
Expand All @@ -212,8 +234,7 @@ sub float {
else {
@arr = unpack 'f*', $data;
}
$pffmt = '%6.6e ';
$strfmt = $pffmt x (scalar @arr);
$strfmt = '%6.6e ' x (scalar @arr);
}

sub decimal {
Expand All @@ -223,8 +244,7 @@ sub decimal {
else {
@arr = unpack 's*', $data;
}
$pffmt = '%5d ';
$strfmt = $pffmt x (scalar @arr);
$strfmt = '%5d ' x (scalar @arr);
}

sub long {
Expand All @@ -236,8 +256,7 @@ sub long {
else {
@arr = unpack 'L*', $data;
}
$pffmt = '%10ld ';
$strfmt = $pffmt x (scalar @arr);
$strfmt = '%10ld ' x (scalar @arr);
}

sub octal2 {
Expand All @@ -247,8 +266,7 @@ sub octal2 {
else {
@arr = unpack 'S*', $data;
}
$pffmt = '%.6o ';
$strfmt = $pffmt x (scalar @arr);
$strfmt = '%.6o ' x (scalar @arr);
}

sub hex {
Expand All @@ -258,8 +276,7 @@ sub hex {
else {
@arr = unpack 'S*', $data;
}
$pffmt = '%.4x ';
$strfmt = $pffmt x (scalar @arr);
$strfmt = '%.4x ' x (scalar @arr);
}

sub diffdata {
Expand All @@ -268,7 +285,7 @@ sub diffdata {
}

sub help {
print "usage: od [-bcdfiloxv] [-A radix] [-j skip_bytes] [-N limit_bytes] filename\n";
print "usage: od [-bcdfiloxv] [-A radix] [-j skip_bytes] [-N limit_bytes] [file]...\n";
exit EX_FAILURE;
}
__END__
Expand All @@ -279,12 +296,12 @@ od - dump files in octal and other formats
=head1 SYNOPSIS
B<od> [ I<-bcdfiloxv> ] [I<-j skip_n_bytes>] [I<-N read_n_bytes>] [ I<-A radix> ] F<filename>
B<od> [ I<-bcdfiloxv> ] [I<-j skip_n_bytes>] [I<-N read_n_bytes>] [ I<-A radix> ] [ F<file>... ]
=head1 DESCRIPTION
The B<od.pl> writes to the standard output the contents of the given
files, or of the standard input if the name `-' is given. Each line
B<od> writes to the standard output the contents of the given
files, or of the standard input if no files are specified. Each line
of the output consists of the offset in the input file in the leftmost
column of each line, followed by one or more columns of data from the
file, in a format controlled by the options. By default, od prints the
Expand Down

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