Here is a list of all variables with links to the files they belong to:

• h_list : history.c
• history_file : history.c
• job_store : job_store.c
• optarg : cd.c, echo.c, history.c, ls.c, pwd.c
• opterr : cd.c, echo.c, history.c, ls.c, pwd.c
• optind : cd.c, echo.c, history.c, ls.c, pwd.c
• optopt : cd.c, echo.c, history.c, ls.c, pwd.c
• shell_pgid : executor.c
• shell_terminal : executor.c