Which command is used in shell scripting to ping an IP address?

The command used in shell scripting to ping an IP address is "ping." This command is a network utility that tests the reachability of a host on an Internet Protocol (IP) network. By sending Internet Control Message Protocol (ICMP) echo request packets to the target IP address and waiting for a response, the command measures round-trip time and provides statistics about packet loss and latency.

Using "ping" is fundamental for network troubleshooting as it helps verify if a host is active and reachable. In scripts, this command can automate the process of checking connectivity, making it a vital tool for system administrators and network engineers.

The other options do not serve this purpose: "trace" might refer to tools like "traceroute," which shows the path packets take to reach a destination, "check" is not a standard network command in this context, and "lookup" could pertain to DNS lookups, which is unrelated to "pinging" an IP address.