Re^2: tracing system calls a perl script is making

Anything between those is your program

...which while block buffered, on my box is optimized into a single write() system call ;-)

strace perl -le 'INIT{ print "About to start running code" }
END{print "code ending"}
print "hello"' 2>&1 | less
execve("/usr/bin/perl", ["perl", "-le", "INIT{ print \"About to start 
+runn"...], [/* 51 vars */]) = 0
brk(0)                                  = 0x1bc9000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 
+0) = 0x7fc0fdf2f000
...
rt_sigaction(SIGIO, NULL, {SIG_DFL, [], 0}, 8) = 0
rt_sigaction(SIGSYS, NULL, {SIG_DFL, [], 0}, 8) = 0
write(1, "About to start running code\nhell"..., 46About to start runn
+ing code
hello
code ending
) = 46
exit_group(0)                           = ?
+++ exited with 0 +++
[download]

I wished only half of the programs in my linux distro were half as good as the perl optimizer. Not to mention the stuff I am perlpetrating :)

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Re^3: tracing system calls a perl script is making by BrowserUk (Patriarch) on May 31, 2013 at 18:46 UTC
He can use warn or print STDERR to prevent that. With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply]
Re^4: tracing system calls a perl script is making by shmem (Chancellor) on May 31, 2013 at 19:11 UTC
Of course. Setting $\| to true also helps. TIMTOWTDI :-)	[reply]
Re^5: tracing system calls a perl script is making by BrowserUk (Patriarch) on May 31, 2013 at 20:43 UTC
I'm generally suspicious of $\| ability to ensure that stdout and stderr coordinate when outputting to a file. Hence advocating outputting to the same handle. I'd swear I've had problems in the past; but it is possible that it was due to threading rather than IO per se. With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply]