ver_linux: Drop redundant calls to system() to test if file is readable (1c9a4be5) · Commits · 戴 / test

Running 'test -r' on an awk variable name whose value is an empty string results in test being run with no arguments, and causes system() to return 0, which indicates success when used to test values returned by function calls. This results in code within the if blocks being run when it should not be. Instead of testing if a file is accessible and readable via calls to system("test -r " file), rely on the value returned by getline to perform this kind of testing. Getline returns -1 on error, with the code within the while loops not being run. Signed-off-by:

Alexander Kapshuk <alexander.kapshuk@gmail.com> Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scripts/ver_linux

+11 −17

Original line number	Diff line number	Diff line
		@@ -31,7 +31,6 @@ BEGIN {
		printversion("Isdn4k-utils", version("isdnctrl"))
		printversion("Nfs-utils", version("showmount --version"))

		if (system("test -r /proc/self/maps") == 0) {
		while (getline <"/proc/self/maps" > 0) {
		n = split($0, procmaps, "/")
		if (/libc.*so$/ && match(procmaps[n], /[0-9]+([.]?[0-9]+)+/)) {
		@@ -40,7 +39,6 @@ BEGIN {
		break
		}
		}
		}

		printversion("Dynamic linker (ldd)", version("ldd --version"))

		@@ -50,9 +48,7 @@ BEGIN {
		break
		}
		}
		if (system("test -r " libcpp) == 0)
		printversion("Linux C++ Library", version("readlink " libcpp))

		printversion("Procps", version("ps --version"))
		printversion("Net-tools", version("ifconfig --version"))
		printversion("Kbd", version("loadkeys -V"))
		@@ -62,14 +58,12 @@ BEGIN {
		printversion("Udev", version("udevadm --version"))
		printversion("Wireless-tools", version("iwconfig --version"))

		if (system("test -r /proc/modules") == 0) {
		while ("sort /proc/modules" \| getline > 0) {
		mods = mods sep $1
		sep = " "
		}
		printversion("Modules Loaded", mods)
		}
		}

		function version(cmd, ver) {
		cmd = cmd " 2>&1"

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