search a particular line and store it in another file using tcl

Question

I have to look into a file log_file.txt which looks something like this:

*Jun 20 16:03:52.482 IST: DSL 0-FW: Data0:
*Jun 20 16:03:52.482 IST: DSL 0-FW: 0x20 0x7 
*Jun 20 16:03:52.482 IST: DSL 0-FW: Read from ID 0x369
*Jun 20 16:15:32.591 IST: DSL 0: IPC: Msg_type (4)
*Jun 20 16:15:33.591 IST: DSL 0: IPC: Msg_type (4)
*Jun 20 16:15:33.591 IST: DSL 0: IPC: Msg_type (4)
*Jun 20 16:15:33.839 IST: %LINK-3-UPDOWN: Interface changed state to down
*Jun 20 16:06:21.848 IST: DSL 0-FW: PHY: ack_control: id:0x1
*Jun 20 16:06:21.848 IST: DSL 0-FW: PHY: ackcontrol: 
*Jun 20 16:06:22.192 IST: DSL 0-FW: PHY: ack_control:

Here I have to search for lines containing DSL 0-FW: and store the line in another file. But I have to exclude the ones with DSL 0-FW: PHY . Is there a possible way to do this?

Answer 1

You could read the file line by line and use string first to filter on the lines you need in the other file. string first returns the position of a particular smaller string into a larger string. It returns -1 if the smaller string is not found.

# Assuming that the script is in the same directory as the file... otherwise 
# replace by the file path

# Read the log file
set fin [open "log_file.txt" r]
# Open a file for writing
set fout [open "output.txt" w]

# Read line by line
while {[gets $fin line] != -1} {
    # Check if "DSL 0-FW:" is in the line, if found, proceed
    if {[string first "DSL 0-FW:" $line] != -1} {

        # Check if "DSL 0-FW:" is in the line, if not found, proceed
        if {[string first "DSL 0-FW: PHY" $line] == -1} {
            puts $fout $line
        }
    }
}

close $fin
close $fout

Or you could perhaps use a regexp:

while {[gets $fin line] != -1} {
    # Check if "DSL 0-FW:" without " PHY" is in the line, if found, proceed
    if {[regexp -- {DSL 0-FW:(?! PHY)} $line]} {
        puts $fout $line
    }
}

Where DSL 0-FW:(?! PHY) will match if there is a DSL 0-FW: not followed by a PHY .

---

Actually, you could even use string match :

while {[gets $fin line] != -1} {
    # Check if "DSL 0-FW:" is in the line, if found, proceed
    if {[string match "DSL 0-FW:" $line]} {

        # Check if "DSL 0-FW:" is in the line, if not found, proceed
        if {![string match "DSL 0-FW: PHY" $line]} {
            puts $fout $line
        }
    }
}

Answer 2

Assuming it's not a problem to read the whole log file into memory:

set all [split [read -nonewline "log.file"] \n]
set wanted [lsearch -all -inline -regex {DSL 0-FW: (?!PHY:)} $lines]
set fh [open "partial.file" w]
puts $fh [join $wanted \n]
close $fh

This uses a negative lookahead to filter out the lines you don't want: http://tcl.tk/man/tcl8.5/TclCmd/re_syntax.htm#M25