Some useful commands

1. $ enscript -2Gr prmPlanner.H -o prmPlanner.ps
2. Search for a string in the files:
   $ grep -l 'DistGaussSample*' *.C
3. At command:
   $ at 1200 [ENTER] command CTRL-D
4. Counting occurrences:
   $ grep word file.txt |wc -l
5. Counting the number of lines in a directory:
   wc -l *
6. The installation of boost has some problems related with the disjoint sets implementation. Adding
   #include boost/pending/disjoint_sets.hpp in the file
   /graph/detail/incremental_components.hpp> solves the issue.
7. Some old codes complain about CLK_TCK:
   #ifndef CLK_TCK
   #define CLK_TCK CLOCKS_PER_SEC
   #endif
   The definition is not anymore in /usr/include/sys/time.h but on
   /usr/include/time.h