Cameron Simpson wrote: > On 08Dec2006 12:01, Luca <luca.piol@xxxxxxxxxxxxx> wrote: > | How do I capture the linking time and data size of ld? > | > | I mean, example, when I compile a package foo from scratch, what > | commands should I use to save a log file with something like: > | > | /usr/bin/ld: total time in link: [time] > | /usr/bin/ld: data size [size] > > Second part first: the 'size" command reports on the section sizes of > an executable, so if the ld command makes a file "bah", the command: > > size bah > > will report on its size. See "man size" for details. > > For timing, you can get the time with the "time" command. Where you > have "ld foo...", put "time ld foo...". Time writes to standard error, > so you will need to send that somewhere: > > time ld foo... 2>output-file > > However, ld will write its own error messages to stderr too, and you > _don't_ want to interfere with them. This incantation > > time sh -c 'exec 2>&3 3>&-; exec ld foo...' 3>&2 2>output-file > > will work around that, sending time's stderr to the output-file and ld's > stderr wherever the original stderr went (usually your terminal). It > takes a copy of the original stderr and the reattaches the copy as stderr > inside the sh command. > > Finally, "time" is often a builtin command in shells. You may get better > behaviour by saying "/usr/bin/time" instead of just "time". That will > run the system "time" executable rather than whatever your shell provides > internally. > > Cheers, > Thanks Cameron; I read something about using gprof and profiling but wasn't 100% sure so I thought better ask.
