This program is using Informix 4GL. The purpose is to delete the report. Well actually it works well, but the problem is that only a specific user can delete the physical file of the report, which means the admin. Other user can delete the report in database but not the physical path. So I need to catch the error in syntax command rm -f. I tried to use WHENEVER ERROR but it couldn't catch it. Does anyone know how to do it? This is the code for deleting the report:
DELETE FROM sysrpt
WHERE srpt_seq_no = p_sysrpt.srpt_seq_no
LET sel_rpt_id = ""
LET sel_rpt_id = p_sysrpt.srpt_pgm_id CLIPPED, ".",
p_sysrpt.srpt_seq_no USING "<<<<<<"
LET sel_rpt_id = sel_rpt_id CLIPPED
LET prt_comand = "\\rm -f ", rpt_path CLIPPED, sel_rpt_id CLIPPED
LET prt_comand = prt_comand CLIPPED
RUN prt_comand
I don't think you'll be able to capture the full error message unless you redirect stdout/stderr to another file as part of the rm command. You can get the return code from the shell command back into the 4gl program by using the RETURNING clause of the RUN statement, e.g. you could add the following after "RUN prt_command":
RUN prt_comand RETURNING p_return_code
From memory, I believe you need to MOD 256 the return code.
This sounds like a classic X-Y problem, where the real issue is the access permissions of the report as originally generated.
Perhaps the report file should be chmod-ed after generation to allow others to delete it, or the app users should have a correctly set umask.
Note that rm -f returns success even when it fails to remove the file, or the file does not exist. If you want rm to return an error, you must not tell it not to return an error.
Otherwise, the advice to use:
RUN prt_command RETURNING p_retcode
is correct. If the value of p_retcode is not zero, the command failed in some way.
The line copied below is superfluous:
LET prt_comand = prt_comand CLIPPED
If prt_command is a CHAR variable, then the stored result is blank-padded again (all CHAR variables are stored blank-padded to full length). If prt_command is a VARCHR variable, the previous assignment with CLIPPED already removed trailing blanks.
It is not clear to me why you are using a backslash before the rm command. Are you avoiding aliases? If so, time to get rid of the alias for rm; it is lethal in the long term. Learn to use the raw command correctly. If you ever get to a machine without the alias, you won't be protected and you will misuse the command without whatever safety net the alias purports to provide.
Related
In my code I am attempting to read in output files that may or may not have a formatted integer in the first line of the file. To aid backwards compatibility I am attempting to be able to read in both examples as shown below.
head -n 3 infile_new
22
8
98677.966601475651 -35846.869655806520 3523978.2959464169
or
head -n 3 infile_old
8
98677.966601475651 -35846.869655806520 3523978.2959464169
101205.49395364164 -36765.047712555031 3614241.1159234559
The format of the top line of infile_new is '(i5)' and so I can accommodate this in my code with a standard read statement of
read(iunit, '(I5)' ) n
This works fine, but if I attempt to read in infile_old using this, I as expected get an error. I have attempted to get around this by using the following
read(iunit, '(I5)' , iostat=ios, err=110) n
110 if(ios == 0) then
print*, 'error in file, setting n'
naBuffer = na
!rewind(iunit) #not sure whether to rewind or close/open to reset file position
close(iunit)
open (iunit, file=fname, status='unknown')
else
print*, "Something very wrong in particle_inout"
end if
The problem here is that when reading in either the old or new file the code ends up in the error loop. I've not been able to find much documentation on using the read statement in this way, but cannot determine what is going wrong.
My one theory was my use of ios==0 in the if statement, but figured since I shouldn't have an error when reading the new file it shouldn't matter. It would be great to know if anyone knows a way to catch such errors.
From what you've shown us, after the code executes the read statement it executes the statement labelled 110. Then, if there wasn't an error and iostat==0 the true branch of the if construct is executed.
So, if there is an error in the read the code jumps to that statement, if there isn't it walks to the same statement. The code doesn't magically know to not execute the code starting at label 110 if there isn't an error in the read statement. Personally I've never used both iostat and err in the same read statement and here I think it's tripping you up.
Try changing the read statement to
read(iunit, '(I5)' , iostat=ios) n
You'd then need to re-work your if construct a bit, since iostat==0 is not an error condition.
Incidentally, to read a line which is known to contain only one integer I wouldn't use an explicit format, I'd just use
read(iunit, * , iostat=ios) n
and let the run-time worry about how big the integer is and where to find it.
There is quite a common issue in unix world, that is when you start a process with parameters, one of them being sensitive, other users can read it just by executing ps -ef. (For example mysql -u root -p secret_pw
Most frequent recommendation I found was simply not to do that, never run processes with sensitive parameters, instead pass these information other way.
However, I found that some processes have the ability to change the parameter line after they processed the parameters, looking for example like this in processes:
xfreerdp -decorations /w:1903 /h:1119 /kbd:0x00000409 /d:HCG /u:petr.bena /parent-window:54526138 /bpp:24 /audio-mode: /drive:media /media /network:lan /rfx /cert-ignore /clipboard /port:3389 /v:cz-bw47.hcg.homecredit.net /p:********
Note /p:*********** parameter where password was removed somehow.
How can I do that? Is it possible for a process in linux to alter the argument list they received? I assume that simply overwriting the char **args I get in main() function wouldn't do the trick. I suppose that maybe changing some files in /proc pseudofs might work?
"hiding" like this does not work. At the end of the day there is a time window where your password is perfectly visible so this is a total non-starter, even if it is not completely useless.
The way to go is to pass the password in an environment variable.
I don't find a way to check the free space available in a device using Haxe, Openfl, Lime or another library.
I would like to avoid download data that will exceed the size recommended for an app in each device.
What do you do to check that?
Try creating a file of that size! Then either delete it or reopen and write (not append) over its contents.
I don't know whether all platforms Haxe supports will work fine with this trick, but this algorithm is reported to work in many places and languages (I personally tested it in Ruby and saw the same suggestion for C++/.NET). To check whether X bytes of disk space are available:
open a new file for writing
seek X-1 bytes from the beginning
write a byte of data (whatever you want, 0, 42...)
close the file (probably unrelated to the task at hand, but don't forget to do that anyway)
If there's insufficient disk space, you'll likely get an exception at some point in this algorithm. You'll have to find out what errors to expect and process them properly.
Using ihx I've found this is working and requires nothing but Haxe Standard Library:
haxe interactive shell v0.3.4
type "help" for help
>> import sys.io.*;
>> var f = File.write('loca', true)
sys.io.FileOutput : { __f => #abstract }
>> f.seek(39999, FileSeek.SeekBegin)
Void : null
>> f.writeByte(0)
Void : null
>> f.close()
Void : null
After these manipulations, I had a file named loca of exactly 40000 bytes in my working directory.
By the way, be careful when doing things like these in ihx since it re-runs the entire session with the last entered line appended each time.
Ongoing experimentation:
However, when there's insufficient disk space, it may not fail with errors. In this case you'll have to check the real size with sys.FileSystem.stat(path).size. And don't forget to delete the file if there's not enough space.
I have R code as below. Below code resides in a file called 'iot.R'. I am executing it in Linux.
I want to print content of variable 'fileinformation' to a file mentioned by file=fileConn...
I thought that the 3rd line will solve the issue, but it is not giving the required output :(
fileinformation = system(paste("file", filenames[1]))
#print(fileinformation)
cat(print(fileinformation),"\r\n","\r\n", file=fileConn)
When I run the file, i get below result. It prints to my screen, rather than writing to the file :(
> source('iot.R')
CH7Data_20130401T135010.csv: ASCII text, with CRLF line terminators
[1] 0
--------------------update1
I also tried below command, but didnt get the expected rsult
cat(capture.output(fileinformation),"\r\n","\r\n", file=fileConn)
You need to set the intern argument to TRUE in your call to system. For instance:
fileinformation<-system("file cinzia_2.gif",intern=TRUE)
fileinformation
#[1] "cinzia_2.gif: GIF image data, version 89a, 640 x 640"
Of course I tried a file on my pc. Setting intern to TRUE the return value of system becomes the console output of the command. Then, when you call cat, you don't need to enclose fileinformation into print, but a simple cat(fileinformation,"\r\n","\r\n", file=fileConn) will suffice.
Hi Just a comment as I dont have enough rep to comment in the normal way. but cant you use
write.table
to save the output to a file? It may be easier?
Perl and html, CGI on Linux.
Issue with file path name, being passed in a form field, to a CGI on server.
The issue is with the Linux file path, not the PC side.
I am using 2 programs,
1) program written years ago, dynamic html generated in a perl program, and presented to the user as a form. I modified by inserting the needed code to allow a the user to select a file from their PC, to be placed on the Linux machine.
Because this program already knew the filepath, needed on the linux side, I pass this filepath in a hidden form field, to program 2.
2) CGI program on Linux side, to run when form on (1) is posted.
Strange issue.
The filepath that I pass, has a very strange issue.
I can extract it using
my $filepath = $query->param("serverfpath");
The above does populate $filepath with what looks like exactly the correct path.
But it fails, and not in a way that takes me to the file open error block, but such that the call to the CGI script gives an error.
However, if I populate $filepath with EXACTLY the same string, via hard coding it, it works, and my file successfully uploads.
For example:
$fpath1 = $query->param("serverfpath");
$fpath2 = "/opt/webhost/ims/DOCURVC/data"
A comparison of $fpath1 and $fpath2 reveals that they are exactly equal.
A length check of $fpath1 and $fpath2 reveals that they are exactly the same length.
I have tried many methods of cleaning the data in $fpath1.
I chomp it.
I remove any non standard characters.
$fpath1 =~ s/[^A-Za-z0-9\-\.\/]//g;
and this:
my $safe_filepath_characters = "a-zA-Z0-9_.-/";
$fpath1 =~ s/[^$safe_filepath_characters]//g;
But no matter what I do, using $fpath1 causes an error, using $fpath2 works.
What could be wrong with the data in the $fpath1, that would cause it to successfully compare to $fpath2, yet not be equal, visually look exactly equal, show as having the exact same length, but not work the same?
For the below file open block.
$upload_dir = $fpath1
causes complete failure of CGI to load, as if it can not find the CGI (which I know is sometimes caused by syntax error in the CGI script).
$uplaod_dir = $fpath2
I get a successful file upload
$uplaod_dir = ""
The call to the cgi does not fail, it executes the else block of the below if, as expected.
here is the file open block:
if (open ( UPLOADFILE, ">$upload_dir/$filename" ))
{
binmode UPLOADFILE;
while ( <$upload_filehandle> )
{
print UPLOADFILE;
}
close UPLOADFILE;
$msgstr="Done with Upload: upload_dir=$upload_dir filename=$filename";
}
else
{
$msgstr="ERROR opening for upload: upload_dir=$upload_dir filename=$filename";
}
What other tests should I be performing on $fpath1, to find out why it does not work the same as its hard-coded equivalent $fpath2
I did try character replacement, a single character at a time, from $fpath2 to $fpath1.
Even doing this with a single character, caused $fpath1 to have the same error as $fpath2, although the character looked exactly the same.
Is your CGI perhaps running perl with the -T (taint mode) switch (e.g., #!/usr/bin/perl -T)? If so, any value coming from untrusted sources (such as user input, URIs, and form fields) is not allowed to be used in system operations, such as open, until it has been untainted by using a regex capture. Note that using s/// to modify it in-place will not untaint the value.
$fpath1 =~ /^([A-Za-z0-9\-\.\/]*)$/;
$fpath1 = $1;
die "Illegal character in fpath1" unless defined $fpath1;
should work if taint mode is your issue.
But it fails, and not in a way that takes me to the file open error block, but such that the call to the CGI script gives an error.
Premature end of script headers? Try running the CGI from the command line:
perl your_upload_script.cgi serverfpath=/opt/webhost/ims/DOCURVC/data