go to nirgam-2.1 folder, in it open MakeFile.defs set
SYSTEMC = /usr/local/systemc-2.3.1
rubina@rubina-VB:~/Desktop/nirgam 2.1$ make ultraclean
rubina@rubina-VB:~/Desktop/nirgam 2.1$ make
rubina@rubina-VB:~/Desktop/nirgam 2.1$ ./nirgam
again there will be error
./nirgam: error while loading shared libraries:
libsystemc-2.3.1.so: cannot open shared object file: No such file or directory
set path
rubina@rubina-VB:~/Desktop/nirgam 2.1$ export LD_LIBRARY_PATH=/usr/local/systemc-2.3.1/lib-linux/
rubina@rubina-VB:~/Desktop/nirgam 2.1$ ./nirgam
again one error
rubina@rubina-VB:~/Desktop/nirgam 2.1$ export SC_SIGNAL_WRITE_CHECK=DISABLE
rubina@rubina-VB:~/Desktop/nirgam 2.1$ ./nirgam
now nirgam simulation will be succes full
for next time use of nirgam, update bashrc, so that dont have to write export on every run:-
rubina@rubina-VB:~/Desktop/nirgam 2.1$ sudo gedit ~/.bashrc
export SYSTEMC_HOME=/usr/local/systemc-2.3.1/
export LD_LIBRARY_PATH=/usr/local/systemc-2.3.1/lib-linux/
export SC_SIGNAL_WRITE_CHECK=DISABLE
rubina@rubina-VB:~/Desktop/nirgam 2.1$ exec bash