Inserting lines in a multiline command using a for loop in a bash script - linux

Question

I have a bash script which executes a multi-line command multiple times and I am changing the some values on each iteration. Here is my code below:
for (( peer=1; peer<=$nodesNum;peer++ ))
do
echo "Starting peer $peer"
nodeos -p eosio -d /eosio_data/node$peer --config-dir /eosio_data/node$peer --http-server-address=127.0.0.1:$http \
--p2p-listen-endpoint=127.0.0.1:$p2p --access-control-allow-origin=* \
-p "user$peer" --http-validate-host=false --signature-provider=EOS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV=KEY:5KQwrPbwdL6PhXujxW37FSSQZ1JiwsST4cqQzDeyXtP79zkvFD3 \
--max-transaction-time=1000 --genesis-json /eosio_data/genesis.json --wasm-runtime=wabt --max-clients=2000 -e \
--plugin eosio::chain_plugin --plugin eosio::producer_plugin --plugin eosio::producer_api_plugin \
--plugin eosio::chain_api_plugin \
--p2p-peer-address localhost:8888 \
&>eosio_data/logs/nodeos_stderr$p2p.log & \
sleep 1
http=$((http+1))
p2p=$((p2p+1))
done
I need to add a --p2p-peer-address localhost:$((9010 + $peer)) command multiple times for each peer as part of the multi-line command. I new to bash scripting and I couldn't find a similar example.

Answer 1

It's not entirely clear what you need, but I think it's something like the following. An array of --p2p-peer-address options is created, then incorporated
into the larger set of common options. Each call to nodeos then has some peer-specific options in addition to the common options.
# for example
HTTP_BASE=8080
P2P_BASE=12345
# Set of --p2p-peer-address options for shared by all calls.
for ((peer=1; peer <= $nodesNum; peer++)); do
peer_args+=(
--p2p-peer-address
localhost:$((9010+$peer))
)
done
# These are the same for all calls
fixed_args=(
-p eosio
"--access-control-allow-origin=*"
--http-validate-host=false
--signature-provider=EOS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV=KEY:5KQwrPbwdL6PhXujxW37FSSQZ1JiwsST4cqQzDeyXtP79zkvFD3
--max-transaction-time=1000
--genesis-json /eosio_data/genesis.json
--wasm-runtime=wabt
--max-clients=2000
-e
--plugin eosio::chain_plugin
--plugin eosio::producer_plugin
--plugin eosio::producer_api_plugin
--plugin eosio::chain_api_plugin
--p2p-peer-address localhost:8888
"${peer_args[#]}"
)
for ((peer=1; peer<=$nodesNum; peer++)); do
# Call-specific arguments, followed by common arguments.
# $peer is either incorporated into each argument value
nodeos -d /eosio_data/node$peer \
--config-dir /eosio_data/node$peer \
--http-server-address=127.0.0.1:$((HTTP_BASE + $peer)) \
--p2p-listen-endpoint=127.0.0.1:$((P2P_BASE + $peer)) \
-p "user$peer" \
"${fixed_args[#]}" \
&> eosio_data/logs/nodeos_stderr$((P2P_BASE + $peer)).log &
sleep 1
done
To avoid having each instance of nodeos try to connect to itself, build peer_args anew on each iteration of the loop. Remove "${peer_args[#]}" from the definition of fixed_args, then adjust the main loop like so:
for ((peer=1; peer <= $nodesNum; peer++)); do
peer_args=()
for ((neighbor=1; neighbor <= $nodesNum; neighbor++)); do
(( neighbor == peer )) && continue
peer_args+=( --p2p-peer-address localhost:$((9010+peer)) )
done
nodeos -d /eosio_data/node$peer \
--config-dir /eosio_data/node$peer \
--http-server-address=127.0.0.1:$((HTTP_BASE + $peer)) \
--p2p-listen-endpoint=127.0.0.1:$((P2P_BASE + $peer)) \
-p "user$peer" \
"${fixed_args[#]}" \
"${peer_args[#]}" \
&> eosio_data/logs/nodeos_stderr$((P2P_BASE + $peer)).log &
sleep 1
done

Answer 2

I think you were very close. The expression you authored --p2p-peer-address localhost:$((9010 + $peer)) can be inserted into your nodeos call as follows:
for (( peer=1; peer<=$nodesNum;peer++ ))
do
echo "Starting peer $peer"
nodeos -p eosio -d /eosio_data/node$peer \
--config-dir /eosio_data/node$peer \
--http-server-address=127.0.0.1:$http \
--p2p-listen-endpoint=127.0.0.1:$p2p \
--access-control-allow-origin=* \
-p "user$peer" \
--http-validate-host=false \
--signature-provider=EOS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV=KEY:5KQwrPbwdL6PhXujxW37FSSQZ1JiwsST4cqQzDeyXtP79zkvFD3 \
--max-transaction-time=1000 --genesis-json /eosio_data/genesis.json --wasm-runtime=wabt --max-clients=2000 -e \
--plugin eosio::chain_plugin --plugin eosio::producer_plugin --plugin eosio::producer_api_plugin \
--plugin eosio::chain_api_plugin \
--p2p-peer-address localhost:$((9010 + $peer)) &>eosio_data/logs/nodeos_stderr$p2p.log &
sleep 1
http=$((http+1))
p2p=$((p2p+1))
done