Sams Teach Yourself Shell Programming in 24 Hours, Second Edition

Hour 8

1:	Which of the following are valid variable names? _FRUIT_BASKET 1_APPLE_A_DAY FOUR-SCORE&7YEARS_AGO Variable
A1:	(a) and (d) are valid variable names. (b) starts with a number thus it is invalid. (c) contains the & character, which is not a valid character for variable names.
2:	Is the following sequence of array assignments valid in sh, ksh, and bash? $ adams[0]=hitchhikers_guide $ adams[1]=restaurant $ adams[3]=thanks_for_all_the_fish $ adams[42]=life_universe_everything $ adams[5]=mostly_harmless
A2:	These assignments are valid in ksh, bash, and zsh, but not in Bourne shell. Bourne shell only supports scalar variables.
3:	Given the preceding array assignments, how would you access the array item at index 5 in the array adams? How would you ...