001#在PATH中查找程序
验证指定程序是否有效或者能否在PATH目录列表中找到
1 #!/bin/bash 2 # 验证指定程序是否有效或者能否在PATH目录列表中找到 3 4 inpath() { 5 cmd=$1 6 ourpath=$2 7 result=1 8 oldIFS=$IFS 9 IFS=":" 10 11 for dir in $ourpath; do 12 if [ -x $dir/$cmd ]; then 13 result=0 14 fi 15 done 16 17 IFS=$oldIFS 18 return $result 19 } 20 21 checkForCmdInPath() { 22 var=$1 23 if [ $var != "" ]; then 24 if [ ${var%${var#?}} = "/" ]; then 25 # 同 ${var:0:1},提取第一个字符 26 if [ ! -x $var ]; then 27 return 1 28 fi 29 elif ! inpath $var "$PATH"; then 30 return 2 31 fi 32 fi 33 } 34 35 if [ $# -ne 1 ]; then 36 echo "Usage: $0 command" >&2 37 exit 1 38 fi 39 40 checkForCmdInPath "$1" 41 42 case $? in 43 0) echo "$1 found in path" 44 ;; 45 1) echo "$1 not found or not executable" 46 ;; 47 2) echo "$1 not found in path" 48 ;; 49 esac 50 exit 0
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