"The -v (verbose) switch tells strace to print the more information about environment for many calls. This is very noticeable on the “stat” call. For instance, the first line of a strace without the verbose option looks like this: 1489 execve("./open-silent.pl", ["./open-silent.pl"], [/* 31 vars */]) = 0 with the verbose option, I see: execve("./open-silent.pl", ["./open-silent.pl"], ["HOSTNAME=nt12199.product.cpanel."..., "TERM=xterm-256color", "SHELL=/bin/bash", "HISTSIZE=1000", "SSH_CLIENT=10.1.7.152 56078 22", "PERL5LIB=/home/mary/perl5/lib/pe"..., "OLDPWD=/home/mary", "PERL_MB_OPT=--install_base "/hom"..., "SSH_TTY=/dev/pts/0", "USER=mary", "LS_COLORS=rs=0:di=01;34:ln=01;36"..., "MAIL=/var/spool/mail/mary", "PATH=/usr/local/jdk/bin:/home/ma"..., "PWD=/home/mary/public_html", "JAVA_HOME=/usr/local/jdk", "EDITOR=pico", "LANG=en_US.UTF-8", "HISTCONTROL=ignoredups", "SHLVL=1", "HOME=/home/mary", "LS_OPTIONS=--color=tty -F -a -b "..., "PERL_LOCAL_LIB_ROOT=/home/mary/p"..., "LOGNAME=mary", "VISUAL=pico", "CVS_RSH=ssh", "CLASSPATH=.:/usr/local/jdk/lib/c"..., "SSH_CONNECTION=10.1.7.152 56078 "..., "LESSOPEN=|/usr/bin/lesspipe.sh %"..., "PERL_MM_OPT=INSTALL_BASE=/home/m"..., "G_BROKEN_FILENAMES=1", "_=/usr/bin/strace"]) = 0"