List (Debugging with GDB)

9.1 Printing Source Lines

To print lines from a source file, use the list command (abbreviated l). By default, ten lines are printed. There are several ways to specify what part of the file you want to print; see Specify Location, for the full list.

Here are the forms of the list command most commonly used:

list linenum: Print lines centered around line number linenum in the current source file.
list function: Print lines centered around the beginning of function function.
list: Print more lines. If the last lines printed were printed with a list command, this prints lines following the last lines printed; however, if the last line printed was a solitary line printed as part of displaying a stack frame (see Examining the Stack), this prints lines centered around that line.
list -: Print lines just before the lines last printed.

By default, GDB prints ten source lines with any of these forms of the list command. You can change this using set listsize:

set listsize count

set listsize unlimited

Make the list command display count source lines (unless the list argument explicitly specifies some other number). Setting count to unlimited or 0 means there’s no limit.

show listsize

Display the number of lines that list prints.

Repeating a list command with RET discards the argument, so it is equivalent to typing just list. This is more useful than listing the same lines again. An exception is made for an argument of ‘-’; that argument is preserved in repetition so that each repetition moves up in the source file.

In general, the list command expects you to supply zero, one or two locations. Locations specify source lines; there are several ways of writing them (see Specify Location), but the effect is always to specify some source line.

Here is a complete description of the possible arguments for list:

list location: Print lines centered around the line specified by location.
list first,last: Print lines from first to last. Both arguments are locations. When a list command has two locations, and the source file of the second location is omitted, this refers to the same source file as the first location.
list ,last: Print lines ending with last.
list first,: Print lines starting with first.
list +: Print lines just after the lines last printed.
list -: Print lines just before the lines last printed.
list: As described in the preceding table.