Go to the first, previous, next, last section, table of contents.
getline
So far we have been getting our input data from @command{awk}'s main
input stream--either the standard input (usually your terminal, sometimes
the output from another program) or from the
files specified on the command line. The @command{awk} language has a
special built-in command called getline that
can be used to read input under your explicit control.
The getline command is used in several different ways and should
not be used by beginners.
The examples that follow the explanation of the getline command
include material that has not been covered yet. Therefore, come back
and study the getline command after you have reviewed the
rest of this Info file and have a good knowledge of how @command{awk} works.
The getline command returns one if it finds a record and zero if
the end of the file is encountered. If there is some error in getting
a record, such as a file that cannot be opened, then getline
returns -1. In this case, @command{gawk} sets the variable
ERRNO to a string describing the error that occurred.
In the following examples, command stands for a string value that represents a shell command.
Go to the first, previous, next, last section, table of contents.