What are the basics of Perl
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I. Foundation of Perl
1. Common command
1.1perl-v displays the Perl version and tests whether Perl is installed
1.2perldoc-tf looks up function information
1.3perldoc-q finds FAQ
1.4perl is an interpreted language and does not need to be compiled; Python is a virtual machine language that needs to be compiled.
II. Perl widget: data, string
1. Escape characters are represented by\
2. QQ _ quotient operator, using non-characters or numbers as qualifiers
3. Title variable $
4.chomp removes newline characters
5. Input device
6. The formatted string refers to scalars directly in the string.
3. Perl control program flow
1. Empty undef
2. Last _
3.exit0 exits the program normally
4. Perl list / array
1.qw operator declaration list
two。 Definition range 1. 20
3. Define array @
4. Reference array element $[index]
5. Find the array size $size=@array
6. Index number of an element
7.localtime returns a list of time elements that represent the current time
8. Forceful foreachhands var (@ array)
9.split function
10.join function
11.sort sorts the array
twelve。 Airship operator
The 13.scalar function, which forcibly converts to a scalar and puts it in a scalar context, returns the quantity put in.
Scalar@_
5. Perl file operation
1.die function
2.How! Used to return the error message of the operating system in the die function
3.warn
4.definedundef
System variables read by 5.$_foreach
Example:
Open (MYFILE, "c:/manifest.mf") | | die "errerrrig"
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