CNIT 340 Substitution

what are the four types of substitution?

filename substitutuion

varibale substitution

command substitution

arithmetic substitution

what is filename subsitution also known as?

globbing

what is the process of globbing?

expanding a strign with some meta-characters (wild characters) to a list of filenames

globbing is case sensitive (t/f)

true

what are the meta characters?

*, ?, [character set]

what does * do?

matches any character zero or more times

what does ? do?

matches any character one time

what does [character set] do?

matches the characters stated one time

match globbing will match every filename, even the hidden ones (t/f)

false

what is the output of 'ls *'

return all visible filenames

the * globbing can be placed as a prefix and suffix (t/f)

true

how does ? globbing compare to * globbing?

? globbing is basically * matching, but for one charater

examining the command 'ls Chapter?.doc'

would 'Chapter1.doc' or 'Chapter01.doc' match?

Chapter1.doc (? globbing does NOT match zero charaters)

you can use multiple ?? for globbing (t/f)

true

examining the command 'ls Chapter??.doc'

would 'Chapter1.doc' appear in the match?

no, but Chapter01.doc would

if ? globbing does not match anything, what does the shell assume?

the filename contained a '?' character (Chapter?.doc)

[character set] match globbing matches zero characters (t/f)

false

examine the command 'ls Chapter0 [0123] .doc'

what would an output be?

Chapter01.doc

Chapter02.doc

Chapter03.doc

etc

how would you negate a set of characters?

ls [!a-z]*

what would ls [!a-z]* match?

any file without a lowercase letter

default value substitutuion is defined as what?

$[ :- }

default value assignment substitutuion is defined as what?

${:=}

substitute when set is defined as what?

${:+}

null value error is defined as what?

{:?}

the shell can perform simple integer math (t/f)

true

solution for integers will only keep the integer portion (t/f)

true