2. Text Analysis tool-awk

General format of the awk command:

awk ' {pattern + action} ' {Filenames}

Call awk:

1. Command-line mode:awk[-F Field-separator]'commands'input-file(s) commands is the real awk command, [-f Domain delimiter] is optional. input-file(s) is the file to be processed. 2The . Shell script will input all awk commands into the file, and then the awk command interpreter as the first line of the script (#bin/awk). 3Insert all awk commands into a separate file, and then call:awk-Fawk-script-fileinput-file(s) among them,The-f option loads the awk script in Awk-script-file.

Built-in variable table:

$	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
Rs	Enter the delimiter for the record, which is the line break by default
OFS	Output field delimiter is blank by default
ORS	Output record delimiter, default is line break
ARGC	Number of command line arguments
Argv	Array of command-line arguments
FILENAME	Current input file name
IGNORECASE	If true, the matching of the case is ignored
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

2. Text Analysis tool-awk