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This wrapper is used to trace sysfs attribute writes > > > +# when the --cmd-trace option is enabled. > > > +_echo() { > > > + echo "$1" > "$2" > > > +} > > > > Stupid question, can't we override the echo function, something like this: > > > > echo() { > > builtin echo "$@" > > builtin echo "$@" >> "/tmp/debug_log.txt" > > } > > How can this work since the sysfs/debugfs/configfs attribute is not an > argument of the echo command? I guess Daniel's idea was to do as follows: echo() { builtin echo "$@" builtin echo "$@" >> "${seqres}.cmdtrace" } This can capture both the value and the filename in the .cmdtrace file. Said that, this will not work when printf is used to write to sysfs/debugfs/configfs attributes. So, I'm tempted to Bart's idea to rename _echo() to _set_attr().