Tuesday, 13 December 2011

Running our PDF Tool commands on Linux Ubuntu Apache PHP server - PdfPageCount example

e.g. with PdfPageCount   available here: http://www.traction-software.co.uk/servertools/pdfpagecount/index.html

su   to switch to root user

cp PdfPageCount /var/www
cp test5.pdf /var/www
chmod 777 /var/www/*


<?php
echo "<HTML>";

$file = './test5.pdf';
$command = './PdfPageCount ';
$out = shell_exec($command. $file.' > /dev/null; echo $?'  );

echo "Page count: ";
echo $out;

echo "</HTML>";
?>

Ubuntu Root password on install? To enable the Root account (i.e. set a password)

You probably just need to enable Root account

To enable the Root account (i.e. set a password) use:

sudo passwd root

then type: su

to switch to root!

Ubuntu Linux 64bit compile error fix - STT_GNU_IFUNC symbol `strcmp' recompile with -fPIE and relink with -pie

Error:
/usr/bin/ld: dynamic STT_GNU_IFUNC symbol `strcmp' with pointer equality in `./libc.a(strcmp.o)' can not be used when making an executable; recompile with -fPIE and relink with -pie

FIX:-
Ignore -pie comment above, add -static to g++   e.g.


ln `g++ -m64 -print-file-name=libstdc++.a`
ln -s `g++ -m64 -print-file-name=libc.a`

g++ -m64 -static -static-libgcc -L.  exefile.cpp -oexefile







Friday, 9 December 2011

Linux error codes

Appendix D. Exit Codes With Special Meanings


Table D-1. Reserved Exit Codes
Exit Code NumberMeaningExampleComments
1Catchall for general errorslet "var1 = 1/0"Miscellaneous errors, such as "divide by zero" and other impermissible operations
2Misuse of shell builtins (according to Bash documentation)empty_function() {}Seldom seen, usually defaults to exit code 1
126Command invoked cannot execute Permission problem or command is not an executable
127"command not found"illegal_commandPossible problem with $PATH or a typo
128Invalid argument to exitexit 3.14159exit takes only integer args in the range 0 - 255 (see first footnote)
128+nFatal error signal "n"kill -9 $PPID of script$? returns 137 (128 + 9)
130Script terminated by Control-C Control-C is fatal error signal 2, (130 = 128 + 2, see above)
255*Exit status out of rangeexit -1exit takes only integer args in the range 0 - 255
According to the above table, exit codes 1 - 2, 126 - 165, and 255 [1] have special meanings, and should therefore be avoided for user-specified exit parameters. Ending a script with exit 127 would certainly cause confusion when troubleshooting (is the error code a "command not found" or a user-defined one?). However, many scripts use an exit 1 as a general bailout-upon-error. Since exit code 1 signifies so many possible errors, it is not particularly useful in debugging.

There has been an attempt to systematize exit status numbers (see /usr/include/sysexits.h), but this is intended for C and C++ programmers. A similar standard for scripting might be appropriate. The author of this document proposes restricting user-defined exit codes to the range 64 - 113 (in addition to 0, for success), to conform with the C/C++ standard. This would allot 50 valid codes, and make troubleshooting scripts more straightforward. [2] All user-defined exit codes in the accompanying examples to this document conform to this standard, except where overriding circumstances exist, as in Example 9-2.

NoteIssuing a $? from the command-line after a shell script exits gives results consistent with the table above only from the Bash or sh prompt. Running the C-shell or tcsh may give different values in some cases.

Notes

[1]Out of range exit values can result in unexpected exit codes. An exit value greater than 255 returns an exit code modulo 256. For example, exit 3809 gives an exit code of 225 (3809 % 256 = 225).
[2]An update of /usr/include/sysexits.h allocates previously unused exit codes from 64 - 78. It may be anticipated that the range of unallotted exit codes will be further restricted in the future. The author of this document will not do fixups on the scripting examples to conform to the changing standard. This should not cause any problems, since there is no overlap or conflict in usage of exit codes between compiled C/C++ binaries and shell scripts.