elif

if condition; then commands; elif condition; then commands; fi

elif is a shell keyword used in bash and other POSIX shells for conditional branching. It's short for "else if" and allows multiple conditions to be tested sequentially.
elif follows an if statement and precedes then. Multiple elif blocks can appear before an optional else. Only the first matching condition's block executes.
This construct is fundamental to shell scripting for implementing multi-way branching logic.

Shell-specific keyword (not a standalone command). Requires matching fi. Whitespace and syntax must be correct. Test brackets need spaces.

elif is part of POSIX shell syntax, inherited from the Bourne shell created by Stephen Bourne at Bell Labs in the 1970s. It provides cleaner syntax than nested if-else blocks.

if(1), else(1), test(1), bash(1)