invoking make from a script

I have a situation where I have to compile a .cc file after changing variables frequently. My script changes the variables in the .cc file

Then i try to compile it first changing into the directory in the shell script by saying cd

and then followed by make. All my shell instructions are saved in a .sh file.

however when i run this i get the error

make: *** No targets specified and no makefile found.  Stop.

but when i manually go to the directory and type make it works.

Wh开发者_运维问答y can't the shell script get the make to work?

EDIT I added the script

#! /bin/sh
# simDir=/home/amm/ns-projects/EURANE/Release



simtime=21
high_users=5
low_users=3
rm user_throughput.txt qos_throughput.txt
echo "Iteration,Users, Low, High,Low average,High average, Average cell througput" >> qos_throughput.txt



for(( husers = 1; husers <= $high_users; husers++ ))      ### Outer for loop ###

do

for(( lusers = 1 ; lusers <= $low_users; lusers++ )) ### Inner for loop ###
do                  

                total_users=0
                let total_users=$husers+$lusers
                echo "$total_users $husers $lusers"
                #Configure the sh file
                num_users=0
                cd /home/chanditha/EURANE_multi_cells_itpp/simulation_scripts
                printf -v num_users "NUM_USERS=\"%d\"" $total_users
                rm hsdpa_ftp_4cells.sh
                perl -pe "s/.*/$num_users/ if $. == 5" hsdpa_ftp_4cells_old.sh > hsdpa_ftp_4cells.sh
                chmod u+x hsdpa_ftp_4cells.sh


                #Configure the awk file
                cd /home/chanditha/EURANE_multi_cells_itpp/simulation_scripts/scripts
                awkline=0
                printf -v awkline "class_cuttoff=max_flow-%d;" $husers
                rm tcp_performance_4cells.awk
                perl -pe "s/.*/$awkline/ if $. == 137" tcp_performance_4cells_old.awk > tcp_performance_4cells.awk




                #Change the directory and go to the .cc file
                cd /home/chanditha/ns-allinone-2.30/ns-2.30/umts
                printf -v cut_off "int cut_off = flow_max_-%d;" $husers;
                rm hsdpalink.cc
                perl -pe "s/.*/$cut_off/ if $. == 2109" hsdpalink_old.cc > hsdpalink.cc
                #Make it
                    make clean && make

done

            cd /home/chanditha/EURANE_multi_cells_itpp/simulation_scripts
            ./hsdpa_ftp_4cells_run_all.sh
done

This will probably take a few iterations. Try running this script and tell us what happens:

cd /home/chanditha/ns-allinone-2.30/ns-2.30/umts
make

Also, your whole architecture sounds shaky. You use a script to change variables in the source, then recompile? For heaven's sake, use a parameter file: the script writes it, the executable reads it.