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Computer/linux

• awk and the data manipulation

  Computer/linux 2008. 8. 22. 00:47

  histogram.dat has the following structure: -100 -99 7 -99 -98 8 -98 -97 11 -97 -96 10 -96 -95 4 -95 -94 6 -94 -93 11 -93 -92 13 -92 -91 11 I want to change "histogram.dat" to the below structure: -100 7 -99 7 -99 8 -98 8 -98 11 -97 11 -97 10 -96 10 -96 4 -95 4 -95 6 -94 6 -94 11 -93 11 -93 13 -92 13 -92 11 awk '{print $1, $3 ; print $2, $3}' histogram.dat > histogram2.dat

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• Make a secure PC with sshd and ufw

  Computer/linux 2008. 8. 20. 04:47

  sshd configuration open /etc/ssh/sshd_config file, change and add the following lines LoginGraceTime 60 PermitRootLogin no MaxAuthTries 3 AllowUsers user_name MaxStartups 3:50:10 LoginGraceTime The server disconnects after this time if the user has not suc- cessfully logged in. If the value is 0, there is no time limit. The default is 120 seconds. MaxAuthTries Specifies the maximum number of aut..

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• declaration of ‘array’ as multidimensional array must have bounds for all dimensions except the first

  Computer/linux 2008. 8. 19. 21:06

  C compiler issues the error : declaration of ‘array’ as multidimensional array must have bounds for all dimensions except the first sum_function (TH1D* inHisto[][]);Solution: sum_function(TH1D* inHisto[][10]); Reference : http://oreilly.com/catalog/cplus2/errata/cplus2.confirmed

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• "Search" example in C

  Computer/linux 2008. 8. 18. 19:34

  header file : #include reference : http://www.gnu.org/software/libc/manual/html_node/Searching-and-Sorting.html#Searching-and-Sortinghttp://www.codecogs.com/reference/c/search.h/ Defining how to compare two int objects: int compare_ints (const void *a, const void *b) { const int *da = (const int *) a; const int *db = (const int *) b; return (*da > *db) - (*da < *db); } return : negative if a “le..

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• warning: incompatible implicit declaration of built-in function ‘strstr’

  Computer/linux 2008. 8. 15. 06:31

  Problem : When I try to compile c program, I met the following error message: warning: incompatible implicit declaration of built-in function ‘strstr’ Analysis : This means that no header file contains the strstr function that I use in the program. Solution : Add the header file according to my function (strstr) #include

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• Try to find the hostname in the Makefile

  Computer/linux 2008. 8. 13. 17:36

  HOSTNAME = $(shell uname -n) or HOSTNAME = $(shell hostname) After that, you can call the hostname as $(HOSTNAME) I added other example MKDIR:= $(shell echo $(ARDMK_DIR)) include $(MKDIR)/arduino-mk/Arduino.mk

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• Mathematica start up error

  Computer/linux 2008. 7. 21. 19:53

  Mathematica start up error with the following error message. add export LANG=en.UTF-8 at the first line of the mathematica script. export LANG=en.UTF-8

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• Keyboard doesnot work in the virtualbox.

  Computer/linux 2008. 7. 12. 04:55

  After installing the VirtualBox OSE on the Ubuntu 8.04, I installed Windows xp. There is a keyboard issue. It can be solved by adding the follwoing lines in the /usr/bin/VBoxManage. GTK_IM_MODULE=none QT_IM_MODULE=none XMODIFIERS=none

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