auxil.tcl

::pwtk::grep_field

::pwtk::grep_field

SYNOPSIS

proc ::pwtk::grep_field {pattern file which_field {index ""}} {

PURPOSE

A "field-segmented" version of ::pwtk::grep command. It returns only a specified field from the lines that matches the pattern.

ARGUMENTS

pattern -- pattern to grep for [pattern matching is that of Tcl's "string match" command]
file -- file to grep
which_field -- which field from the grepped line to return; its meaning/syntax is the same as for the Tcl 'lindex' command; 0 = first field; end = last field
index -- [optional] which match to return; its meaning/syntax is the same as for the Tcl 'lindex' command; 0 = first match; end = last match

SOURCE

    set result ""

    pwtk::lineread line $file {
        if { [string match *$pattern* $line] } {
            lappend result [lindex $line $which_field]
        }
    }

    if { $index != "" } {
        set result [lindex $result $index]
    }

    return $result
}

TABLE OF CONTENTS

::pwtk::grep_field