This cheatsheet includes most of the byebug commands organized by related commands (e.g. breakpoint related commands are together).
To see official help...
| Command |
Aliases |
Example |
Comments |
help |
h |
h |
list top level of all commands |
help cmd |
h cmd-alias |
h n |
list the details of the next command (this works for all commands) |
| Command |
Aliases |
Example |
Comments |
next |
n |
n |
step over to next line in same block or method (or back to calling block/method if at end of current block/method) |
| |
|
n 3 |
step over next N lines (e.g. if on line 11, n 3 will continue and break on line 14) |
step |
s |
s |
step into block or method |
| |
|
s 3 |
step in 3 times |
continue |
c |
c |
continue execution to next breakpoint (or end of program if no breakpoints reached) |
| |
|
c 43 |
continues and stops at line 43 (stopping at breakpoint if encountered first) |
continue! |
c! |
c! |
continue execution to end of program ignoring all breakpoints |
| Command |
Aliases |
Example |
Comments |
info breakpoints |
i b |
i b |
Lists breakpoint id, enabled?, and breakpoint line |
break |
b |
b 33 |
Set breakpoint at specified line (e.g. 33) in the current file |
disable breakpoint |
dis b |
dis b 2 |
Disable breakpoint with id (e.g. 2) (disables all if no id specified) |
enable breakpoint |
en b |
en b 2 |
Enable breakpoint with id (e.g. 2) (disables all if no id specified) |
delete |
del |
del 1 |
Deletes breakpoint with id (e.g. 1) (deletes all if no id specified) |
condition |
cond |
cond 3 i > 3 |
Breaks at breakpoint with id (e.g. 3) only if condition is met |
| |
|
cond 3 |
Removes condition from breakpoint with id (e.g. 3) |
Enabled watch expressions display every time byebug stops.
| Command |
Aliases |
Example |
Comments |
info display |
i d |
i d |
Lists display id, enabled?, and expression being watched |
display |
disp |
disp arg |
Set expression to watch (e.g. arg) everytime the debugger stops |
| |
|
disp |
Lists all display expressions with values |
disable display |
dis d |
dis d 2 |
Disable display with id (e.g. 2) (maybe - disables all if no id specified) |
enable display |
en d |
en d 2 |
Enable display with id (e.g. 2) (maybe - disables all if no id specified) |
undisplay |
undisp |
undisp 1 |
Stop displaying expression with id (e.g. 1) (stops displaying all if no id specified) |
| Command |
Aliases |
Example |
Comments |
var args |
v a |
v a |
show arguments and values for current method |
var local |
v l |
v l |
show local variable and values for current scope (e.g. scope = method or block) |
var instance |
v i |
v i |
show instance variables and values for instance |
| |
|
v i obj |
show instance variables and values for another object (e.g. obj) |
var const |
v c |
v c |
show constants and values for current instance's class |
| |
|
v c klass |
show constants and values for another module/class (e.g. klass) |
var global |
v g |
v g |
show global variables and values |
var all |
v all |
v all |
show local, global, and instance variables and values of self |
| Command |
Aliases |
Example |
Comments |
list= |
l= |
l= |
List 5 before and 4 after the current line pending execution (resets to current stop point) |
list |
l |
l 8-20 |
List specified range of lines (e.g. lines 8-20) |
| |
|
l |
List next 10 lines from current location listed. (l again gives next 10 after that) |
list- |
l- |
l- |
List previous 10 lines from current location listed. (l- again gives previous 10 before that) |
where or backtrace |
w or bt |
w |
display backtrace (w and bt are the same command) |
| |
|
bt |
display backtrace |
