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I'm trying to write the output of strace ls to a file. I know that I need to use > in order to forward output of a command to a file, but it doesn't work. It creates a file but the command prints the output of strace ls to stdout but writes the file name into the file.
$ strace ls > ls_sys.txt
...
strace output
...
$ cat ls_sys.txt
ls_sys.txt
By default strace outputs to stderr. By simply typing man strace, you will have the full documentation of strace. In the manual page, it states that the -o option can be used to output it to a file instead of stderr. You can type man [insert command here] for the vast majority of programs, and have all the documentation you will need to effectively use them.
By default strace outputs to stderr, which is not accessible via grep or file redirection. Good to know! And I looked at the manual page of strace but I didn't see the -o option, my fault. Thanks!
Aug 27, 2020 at 18:11
/ and it will bring a dialog that you can search. In my case, I simply searched for output and found the part of the man page I was looking for.
grep?
For those looking for a command to run:
strace ./elf_file 2>strace_output.txt
strace tracing and the ./elf_file errors to strace_output.txt. For that reason, it's better to use strace -o strace_output.txt ./elf_file or strace -o strace_output.txt ./elf_file 1> stdout.txt 2> stderr.txt if you want traces, stdout and stderr in different files.
Jan 7, 2022 at 12:57
-ooption rather than shell redirectionstrace -o ls_sys.txt ls?