How do I convert LTSpice netlist/asc to a pcb-lesstif netlist?

Then why do you want to do that?

It's probably hopeless. Spice isn't aware of the PCB parts library or symbols or footprints or pinouts.

because gsch2pcb

There may be ways...

It's far from hopeless if you know the format for pcb. Actually there is a commonly used format called PADS from a commercial package. While searching for this name I also found a converter program that may help you... gnetlist I'll let you look it up to see if it will convert for you.

Push come to shove you can figure out what formats your layout program will import you can write a program to convert from the simple LTspice format. Forth is a great language for this.

Sounds like a compound nightmare.

Thanks, that was what I was looking for...

PCB's netlist format is pretty trivial, but using it to import designs... there's a better way :-)

PCB has File->Import option that reads a script that builds the design by specifying all the footprints required, the netlist, and the attributes for everything. It's a plain text file made up of "actions" (pcb functions) which are documented in the PCB manual. You can hook the File->Import button to a Makefile if you want to import from something other than gschem.

PCB's manual is at

I'll add a sample script from my "rainbow LED" project for reference.

Netlist(Freeze) Netlist(Clear) Netlist(Add,unnamed_net12,LED8-2) Netlist(Add,unnamed_net12,TMINUS-1) Netlist(Add,unnamed_net12,LED7-2) Netlist(Add,unnamed_net11,LED7-1) Netlist(Add,unnamed_net11,LED6-2) Netlist(Add,unnamed_net10,R2-1) Netlist(Add,unnamed_net10,U2-7) Netlist(Add,unnamed_net10,U2-6) Netlist(Add,unnamed_net10,U2-3) Netlist(Add,unnamed_net10,U2-2) Netlist(Add,unnamed_net9,LED6-1) Netlist(Add,unnamed_net9,LED5-2) Netlist(Add,unnamed_net8,LED5-1) Netlist(Add,unnamed_net8,LED4-2) Netlist(Add,unnamed_net7,U2-4) Netlist(Add,unnamed_net7,R2-2) Netlist(Add,unnamed_net7,LED4-1) Netlist(Add,unnamed_net6,LED8-1) Netlist(Add,unnamed_net6,LED3-2) Netlist(Add,unnamed_net5,LED3-1) Netlist(Add,unnamed_net5,LED2-2) Netlist(Add,unnamed_net4,TPLUS-1) Netlist(Add,unnamed_net4,U2-1) Netlist(Add,unnamed_net4,U1-1) Netlist(Add,unnamed_net3,U1-7) Netlist(Add,unnamed_net3,U1-6) Netlist(Add,unnamed_net3,U1-3) Netlist(Add,unnamed_net3,U1-2) Netlist(Add,unnamed_net3,R1-1) Netlist(Add,unnamed_net2,LED2-1) Netlist(Add,unnamed_net2,LED1-2) Netlist(Add,unnamed_net1,U1-4) Netlist(Add,unnamed_net1,R1-2) Netlist(Add,unnamed_net1,LED1-1) Netlist(Sort) Netlist(Thaw) ElementList(Start) ElementList(Need,"R2","0603dj.fp","62") ElementSetAttr("R2","device","RESISTOR") ChangePinName("R2", 1, "1") ChangePinName("R2", 2, "2") ElementList(Need,"TMINUS","hole-43mil.fp","unknown") ElementSetAttr("TMINUS","device","terminal") ChangePinName("TMINUS", 1, "terminal") ElementList(Need,"TPLUS","hole-43mil.fp","unknown") ElementSetAttr("TPLUS","device","terminal") ChangePinName("TPLUS", 1, "terminal") ElementList(Need,"LED8","0603dj.fp","unknown") ElementSetAttr("LED8","device","LED") ChangePinName("LED8", 2, "K") ChangePinName("LED8", 1, "A") ElementList(Need,"LED7","0603dj.fp","unknown") ElementSetAttr("LED7","device","LED") ChangePinName("LED7", 2, "K") ChangePinName("LED7", 1, "A") ElementList(Need,"LED6","0603dj.fp","unknown") ElementSetAttr("LED6","device","LED") ChangePinName("LED6", 2, "K") ChangePinName("LED6", 1, "A") ElementList(Need,"U2","SO8","unknown") ChangePinName("U2", 7, "VOUT") ChangePinName("U2", 6, "VOUT") ChangePinName("U2", 4, "ADJ") ChangePinName("U2", 3, "VOUT") ChangePinName("U2", 2, "VOUT") ChangePinName("U2", 1, "VIN") ElementList(Need,"LED5","0603dj.fp","unknown") ElementSetAttr("LED5","device","LED") ChangePinName("LED5", 2, "K") ChangePinName("LED5", 1, "A") ElementList(Need,"LED4","0603dj.fp","unknown") ElementSetAttr("LED4","device","LED") ChangePinName("LED4", 2, "K") ChangePinName("LED4", 1, "A") ElementList(Need,"LED3","0603dj.fp","unknown") ElementSetAttr("LED3","device","LED") ChangePinName("LED3", 2, "K") ChangePinName("LED3", 1, "A") ElementList(Need,"LED2","0603dj.fp","unknown") ElementSetAttr("LED2","device","LED") ChangePinName("LED2", 2, "K") ChangePinName("LED2", 1, "A") ElementList(Need,"U1","SO8","unknown") ChangePinName("U1", 7, "VOUT") ChangePinName("U1", 6, "VOUT") ChangePinName("U1", 4, "ADJ") ChangePinName("U1", 3, "VOUT") ChangePinName("U1", 2, "VOUT") ChangePinName("U1", 1, "VIN") ElementList(Need,"R1","0603dj.fp","62") ElementSetAttr("R1","device","RESISTOR") ChangePinName("R1", 1, "1") ChangePinName("R1", 2, "2") ElementList(Need,"LED1","0603dj.fp","unknown") ElementSetAttr("LED1","device","LED") ChangePinName("LED1", 2, "K") ChangePinName("LED1", 1, "A") ElementList(Done)

This kinda works now...

This works too for importing LT-Spice .asc files into gschem .sym format: