I came to know that there is a BOF function available to use in QBASIC. It is called the Beginning Of File. But, I didn't find any examples over its use. Please help.
Here is an example for a possible BOF function:
' example BOF function in QB
' returns beginning of file
PRINT "Enter filename";: INPUT F$
Handle = FREEFILE
OPEN F$ FOR BINARY AS #Handle
PRINT "BOF="; BOF(Handle)
END
' function to get BOF
FUNCTION BOF (H)
IF LOF(H) > 0 THEN
BOF = 1
ELSE
BOF = 0
END IF
END FUNCTION
Sample to determine if file is at BOF:
' example BOF function in QB
' returns true if at beginning of file.
PRINT "Enter filename";: INPUT F$
Handle = FREEFILE
OPEN F$ FOR BINARY AS #Handle
IF BOF(Handle) THEN
PRINT "File is at BOF"
END IF
END
' function to get BOF
FUNCTION BOF (H)
IF LOC(H) <= 1 THEN
BOF = -1
ELSE
BOF = 0
END IF
END FUNCTION
Related
I am reading a file using fileread() which returns me the entire file. Now I need to read line by line and convert them into process the data. Can I know how I would be able to detect the newline character in Matlab? I tried '\n' and '\r\n' and it doesn't work.
Thanks in advance
For special acharacters either use the char function with the character code (http://www.asciitable.com/) or sprintf (my preferred way for better readability.
For example you are looking for sprintf('\n') or sprintf('\r\n')
char(13) is carriage return \r
char(10) is new line \n
You can read the file line by line (see fgetl):
fid = fopen ( 'file', 'r' );
% Check that it opened okay
if fid ~= -1
while ( true )
line = fgetl ( fid );
% Check for end of file
if line == -1; break; end
%Do stuff with line;
end
fclose ( fid );
end
DECLARE SUB cube(!)
INPUT "Enter a length";l
CALL cube(l)
END
SUB cube(l)
area=6*l^2
PRINT "Area of a cube",area
END SUB
This snip describes calling a subroutine in QBasic to get the area of a cube:
DECLARE SUB Cube(L!)
INPUT "Enter a length"; L!
CALL Cube(L!)
END
SUB Cube (L!)
Area! = 6 * L! ^ 2
PRINT "Area of a cube"; Area!
END SUB
The ! declares a variable as single precision.
I have multiple text files named split01.txt, split02.txt etc... with the data in the format below: (This is what I have)
/tmp/audio_files/n000001.wav;
/tmp/audio_files/n000002.wav;
/tmp/audio_files/n000003.wav;
/tmp/audio_files/p000004.wav;
/tmp/audio_files/p000005.wav;
I would like to create another file with the data taken from the split01.txt, split02.txt etc... file in the format below: (this is the format I would like to see)
[playlist]
NumberOfEntries=5
File000001=n000001.wav
Title000001=n000001.wav
File000002=n000002.wav
Title000002=n000002.wav
File000003=n000003.wav
Title000003=n000003.wav
File000004=p000004.wav
Title000004=p000004.wav
File000005=p000005.wav
Title000005=p000005.wav
Version=2
Can this be done in one instance? The reason I ask is that I'm going to be running/calling the command (awk,grep,sed,etc...) from inside of octave/matlab after the initial process has completed creating the audio files.
example: of what I mean in one instance below: (matlab/octave code)
system(strcat({'split --lines=3600 -d '},dirpathwaveformstmp,fileallplaylistStr,{' '},dirpathwaveformstmp,'allsplit'))
This splits a single file into multiple files with the names allsplit01 allsplit02 etc.. and each file only has a max of 3600 lines.
For those who asked this is creating playlist files for audio files I create with octave/matlab.
Any suggestions?
Here's one way you could do it with awk:
parse.awk
BEGIN {
print "[playlist]"
print "NumberOfEntries=" len "\n"
i = 1
}
{
gsub(".*/|;", "")
printf "File%06d=%s\n" , i, $0
printf "Title%06d=%s\n\n", i, $0
i++
}
END {
print "Version 2"
}
Run it like this:
awk -v len=$(wc -l < infile) -f parse.awk infile
Output:
[playlist]
NumberOfEntries=5
File000001=n000001.wav
Title000001=n000001.wav
File000002=n000002.wav
Title000002=n000002.wav
File000003=n000003.wav
Title000003=n000003.wav
File000004=p000004.wav
Title000004=p000004.wav
File000005=p000005.wav
Title000005=p000005.wav
Version 2
If you're writing your program in Octave, why don't you do it in Octave as well? The language is not limited to numerical analysis. What you're trying to do can be done quite easily with Octave functions.
filepath = "path for input file"
playlistpath = "path for output file"
## read file and prepare cell array for printing
files = strsplit (fileread (filepath)', "\n");
if (isempty (files{end}))
files(end) = [];
endif
[~, names, exts] = cellfun (#fileparts, files, "UniformOutput", false);
files = strcat (names, exts);
files(2,:) = files(1,:);
files(4,:) = files(1,:);
files(1,:) = num2cell (1:columns(files))(:);
files(3,:) = num2cell (1:columns(files))(:);
## write playlist
[fid, msg] = fopen (playlistpath, "w");
if (fid < 0)
error ("Unable to fopen %s for writing: %s", playlistpath, msg);
endif
fprintf (fid, "[playlist]\n");
fprintf (fid, "NumberOfEntries=%i\n", columns (files));
fprintf (fid, "\n");
fprintf (fid, "File%06d=%s\nTitle%06d=%s\n\n", files{:});
fprintf (fid, "Version 2");
if (fclose (fid))
error ("Unable to fclose file %s with FID %i", playlistpath, fid);
endif
I have two files:
(one.txt) looks Like this:
>ENST001
(((....)))
(((...)))
>ENST002
(((((((.......))))))
((((...)))
I have like 10000 more ENST
(two.txt) looks like this:
>ENST001 110
>ENST002 59
and so on for the rest of all ENSTs
I basically would like to replace the ENSTs in the (one.txt) by the combination of the two fields in the (two.txt) so the results will look like this:
>ENST001_110
(((....)))
(((...)))
>ENST002_59
(((((((.......))))))
((((...)))
I wrote a matlab script to do so but since it loops for all lines in (two.txt) it take like 6 hours to finish, so I think using awk, sed, grep, or even perl we can get the result in few minutes. This is what I did in matlab:
frf = fopen('one.txt', 'r');
frp = fopen('two.txt', 'r');
fw = fopen('result.txt', 'w');
while feof(frf) == 0
line = fgetl(frf);
first_char = line(1);
if strcmp(first_char, '>') == 1 % if the line in one.txt start by > it is the ID
id_fold = strrep(line, '>', ''); % Reomve the > symbol
frewind(frp) % Rewind two.txt file after each loop
while feof(frp) == 0
raw = fgetl(frp);
scan = textscan(raw, '%s%s');
id_pos = scan{1}{1};
pos = scan{2}{1};
if strcmp(id_fold, id_pos) == 1 % if both ids are the same
id_new = ['>', id_fold, '_', pos];
fprintf(fw, '%s\n', id_new);
end
end
else
fprintf(fw, '%s\n', line); % if the line doesn't start by > print it to results
end
end
One way using awk. FNR == NR process first file in arguments and saves each number. Second condition process second file, and when first field matches with a key in the array modifies that line appending the number.
awk '
FNR == NR {
data[ $1 ] = $2;
next
}
FNR < NR && data[ $1 ] {
$0 = $1 "_" data[ $1 ]
}
{ print }
' two.txt one.txt
Output:
>ENST001_110
(((....)))
(((...)))
>ENST002_59
(((((((.......))))))
((((...)))
With sed you can at first run only on two.txt you can make a sed commands to replace as you want and run it at one.txt:
First way
sed "$(sed -n '/>ENST/{s=.*\(ENST[0-9]\+\)\s\+\([0-9]\+\).*=s/\1/\1_\2/;=;p}' two.txt)" one.txt
Second way
If files are huge you'll get too many arguments error with previous way. Therefore there is another way to fix this error. You need execute all three commands one by one:
sed -n '1i#!/bin/sed -f
/>ENST/{s=.*\(ENST[0-9]\+\)\s\+\([0-9]\+\).*=s/\1/\1_\2/;=;p}' two.txt > script.sed
chmod +x script.sed
./script.sed one.txt
The first command will form the sed script that will be able to modify one.txt as you want. chmod will make this new script executable. And the last command will execute command. So each file is read only once. There is no any loops.
Note that first command consist from two lines, but still is one command. If you'll delete newline character it will break the script. It is because of i command in sed. You can look for details in ``sed man page.
This Perl solution sends the modified one.txt file to STDOUT.
use strict;
use warnings;
open my $f2, '<', 'two.txt' or die $!;
my %ids;
while (<$f2>) {
$ids{$1} = "$1_$2" if /^>(\S+)\s+(\d+)/;
}
open my $f1, '<', 'one.txt' or die $!;
while (<$f1>) {
s/^>(\S+)\s*$/>$ids{$1}/;
print;
}
Turn the problem on its head. In perl I would do something like this:
#!/usr/bin/perl
open(FH1, "one.txt");
open(FH2, "two.txt");
open(RESULT, ">result.txt");
my %data;
while (my $line = <FH2>)
{
chomp(line);
# Delete leading angle bracket
$line =~ s/>//d;
# split enst and pos
my ($enst, $post) = split(/\s+/, line);
# Store POS with ENST as key
$data{$enst} = $pos;
}
close(FH2);
while (my $line = <FH1>)
{
# Check line for ENST
if ($line =~ m/^>(ENST\d+)/)
{
my $enst = $1;
# Get pos for ENST
my $pos = $data{$enst};
# make new line
$line = '>' . $enst . '_' . $pos . '\n';
}
print RESULT $line;
}
close(FH1);
close(RESULT);
This might work for you (GNU sed):
sed -n '/^$/!s|^\(\S*\)\s*\(\S*\).*|s/^\1.*/\1_\2/|p' two.txt | sed -f - one.txt
Try this MATLAB solution (no loops):
%# read files as cell array of lines
fid = fopen('one.txt','rt');
C = textscan(fid, '%s', 'Delimiter','\n');
C1 = C{1};
fclose(fid);
fid = fopen('two.txt','rt');
C = textscan(fid, '%s', 'Delimiter','\n');
C2 = C{1};
fclose(fid);
%# use regexp to extract ENST numbers from both files
num = regexp(C1, '>ENST(\d+)', 'tokens', 'once');
idx1 = find(~cellfun(#isempty, num)); %# location of >ENST line
val1 = str2double([num{:}]); %# ENST numbers
num = regexp(C2, '>ENST(\d+)', 'tokens', 'once');
idx2 = find(~cellfun(#isempty, num));
val2 = str2double([num{:}]);
%# construct new header lines from file2
C2(idx2) = regexprep(C2(idx2), ' +','_');
%# replace headers lines in file1 with the new headers
[tf,loc] = ismember(val2,val1);
C1( idx1(loc(tf)) ) = C2( idx2(tf) );
%# write result
fid = fopen('three.txt','wt');
fprintf(fid, '%s\n',C1{:});
fclose(fid);
I need to translate this piece of code from Perl to Lua
open(FILE, '/proc/meminfo');
while(<FILE>)
{
if (m/MemTotal/)
{
$mem = $_;
$mem =~ s/.*:(.*)/$1/;
}
elseif (m/MemFree/)
{
$memfree = $_;
$memfree =~ s/.*:(.*)/$1/;
}
}
close(FILE);
So far I've written this
while assert(io.open("/proc/meminfo", "r")) do
Currentline = string.find(/proc/meminfo, "m/MemTotal")
if Currentline = m/MemTotal then
Mem = Currentline
Mem = string.gsub(Mem, ".*", "(.*)", 1)
elseif m/MemFree then
Memfree = Currentline
Memfree = string.gsub(Memfree, ".*", "(.*)", 1)
end
end
io.close("/proc/meminfo")
Now, when I try to compile, I get the following error about the second line of my code
luac: Perl to Lua:122: unexpected symbol near '/'
obviously the syntax of using a directory path in string.find is not like how I've written it. 'But how is it?' is my question.
You don't have to stick to Perl's control flow. Lua has a very nice "gmatch" function which allows you to iterate over all possible matches in a string. Here's a function which parses /proc/meminfo and returns it as a table:
function get_meminfo(fn)
local r={}
local f=assert(io.open(fn,"r"))
-- read the whole file into s
local s=f:read("*a")
-- now enumerate all occurances of "SomeName: SomeValue"
-- and assign the text of SomeName and SomeValue to k and v
for k,v in string.gmatch(s,"(%w+): *(%d+)") do
-- Save into table:
r[k]=v
end
f:close()
return r
end
-- use it
m=get_meminfo("/proc/meminfo")
print(m.MemTotal, m.MemFree)
To iterate a file line by line you can use io.lines.
for line in io.lines("/proc/meminfo") do
if line:find("MemTotal") then --// Syntactic sugar for string.find(line, "MemTotal")
--// If logic here...
elseif --// I don't quite understand this part in your code.
end
end
No need to close the file afterwards.