Expr

expr

Example of expr command that does basic summation
Original author(s)	Dick Haight (AT&T Bell Laboratories)
Developer(s)	Various open-source and commercial developers
Initial release	1979; 45 years ago (1979)
Operating system	Unix, Unix-like, IBM i
Platform	Cross-platform
Type	Command

expr is a command line utility on Unix and Unix-like operating systems which evaluates an expression and outputs the corresponding value. It first appeared in Unix v7. The command is available for Microsoft Windows as part of the UnxUtils collection^[1] of native Win32 ports of common GNU Unix-like utilities.^[2] The expr command has also been ported to the IBM i operating system.^[3]