What is "All shells and programs that use exec*p library calls handle searching"?

Question

I came across this sentence in the following documentation but couldn't understand it, and the link to one of its terms appeared broken to me. Can someone help?

All shells and programs that use exec*p library calls handle searching for executables in directories named in PATH

Source.

Answer 1

You have to parse it:

All shells and programs that use exec*p library calls

next is the verb:

handle searching for executables in directories named in PATH

The exec*p refers to a subset of the system "exec" functions, whose name ends with p, as a clue to the fact that they (as the rest of the sentence says) use the environment variable PATH as a list of directories to search for executable programs with a given name (a parameter of the function).

Further reading:

• execl, execlp, execle, execv, execvp, execvpe - execute a file
  This is an example of the page that Shell and Environment Variables might point to.
• How does execvp run a command?