awk abridged textbook

Awk does not introduce much, one of the best text processing tools

One, built-in variable table

Property	Description
$	Current record (as a single variable)
$1~ $n	The nth field of the current record, separated by FS between fields
Fs	Input field delimiter is blank by default
Nf	The number of fields in the current record, that is, how many columns
Nr	The number of records that have been read is the line number, starting from 1
Rs	Enter the record he defaults to think of a newline character
OFS	The output field delimiter is also a space by default
ORS	Record delimiter for output, default to line break
ARGC	Number of command line arguments
Argv	Array of command-line arguments
FILENAME	The name of the current input file
IGNORECASE	If true, ignores case matching
Argind	argv identifier of the currently processed file
Convfmt	Digital conversion Format%.6g
ENVIRON	UNIX Environment variables
Errno	UNIX System error messages
FieldWidths	Blank delimited string for input field width
FNR	Current Record Count
Ofmt	The output format of the number%.6g
Rstart	The first string matched by the matching function
Rlength	String lengths matched by matching function
Subsep	\034

awk abridged textbook