#! /bin/bash
# inpath -- 验证指定程序是否有效，或者能否在PATH目录列表中找到
in_path()
{
cmd=$1 ourpath=$2 result=1
oldIFS=$IFS IFS=":"
for directory in $ourpath
do
if [ -x $directory/$cmd ] ; then
result=0
fi
done
IFS=$oldIFS
return $result
}
checkForCmdInPath()
{
var=$1
if [ "$var" != "" ] ; then
if [ "${var:0:1}" = "/" ] ; then
if [ ! -x $var ] ; then
return 1
fi
elif ! in_path $var "$PATH"; then
return 2
fi
fi
}
if [ $# -ne 1 ] ; then
echo "Usage: $0 command" >&2
exit 1
fi
checkForCmdInPath "$1"
case $? in
0 ) echo "$1 found in PATH" ;;
1 ) echo "$1 not found or not executable" ;;
2 ) echo "$1 not found in PATH" ;;
esac
exit 0
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