I cannot find out how to see if a command is included in folders of environment variable PATH. I tried the command:
我找不到如何查看一个命令是否包含在环境变量路径文件夹中。我试着命令:
$type -t $command
but it doesn't work.
但它不工作。
Can anyone help me?
谁能帮我吗?
2 个解决方案
#1
2
This should work:
这应该工作:
if [[ $(type -p command) ]]; then
echo "Found"
else
echo "Not Found"
fi
You can use -t too (See exceptions at bottom.).
您也可以使用-t(见下面的异常)。
Or (only testing the exit status with type):
或(仅用类型测试退出状态):
if type command >& /dev/null; then
echo "Found"
else
echo "Not Found"
fi
Note: See exceptions at bottom.
注意:请参见下面的异常。
Another solution (using hash):
另一个解决方案(使用散列):
if [[ ! $(hash command 2>&1) ]]; then
echo "Found"
else
echo "Not Found"
fi
Note: See exceptions at bottom.
注意:请参见下面的异常。
Exceptions:
例外:
type command
type help
hash command
hash help
type -t command
type -t help
command and help are bash built-ins, they are not in any path in PATH environment variable. So the other methods except the first one (with -p option) will Print out Found for bash built-in commands which are not in any path in environment PATH variable.
命令和帮助是bash内置的，它们不在路径环境变量中的任何路径中。因此，除了第一个方法(带有-p选项)之外的其他方法将输出bash内置命令，这些命令在环境路径变量的任何路径中都没有。
Better use the first method (with -p option) if you only want to check if it's located in the paths in PATH environment variable.
如果您只想检查它是否位于PATH环境变量中的路径，最好使用第一个方法(带有-p选项)。
Or if you want to use type -t then change the if statement like this:
或者如果你想使用-t类型，那么改变if语句如下:
if [[ $(type -t command) == file ]]; then
#2
0
Do you mean looking at your path? Similar to:
你是说看着你的路吗?类似于:
$ set | grep PATH
Oh, now I understand. Checking for an executable in the path is fairly easy. I usually use something like the following:
哦,现在我明白了。检查路径中的可执行文件相当容易。我通常使用如下内容:
## test for exe in PATH or exit
exevar="$(which exe 2>/dev/null)"
[ x = x$exevar ] && { echo "'exe' not in path"; exit 1; }
## exe in path, continue
echo "exevar = $exevar"
or use type -p to eliminate the call to which
或者使用-p类型消除对which的调用
## test for exe in PATH or exit
exevar="$(type -p exe 2>/dev/null)"
[ x = x$exevar ] && { echo "'exe' not in path"; exit 1; }
## exe in path, continue
echo "exevar = $exevar"
#1
2
This should work:
这应该工作:
if [[ $(type -p command) ]]; then
echo "Found"
else
echo "Not Found"
fi
You can use -t too (See exceptions at bottom.).
您也可以使用-t(见下面的异常)。
Or (only testing the exit status with type):
或(仅用类型测试退出状态):
if type command >& /dev/null; then
echo "Found"
else
echo "Not Found"
fi
Note: See exceptions at bottom.
注意:请参见下面的异常。
Another solution (using hash):
另一个解决方案(使用散列):
if [[ ! $(hash command 2>&1) ]]; then
echo "Found"
else
echo "Not Found"
fi
Note: See exceptions at bottom.
注意:请参见下面的异常。
Exceptions:
例外:
type command
type help
hash command
hash help
type -t command
type -t help
command and help are bash built-ins, they are not in any path in PATH environment variable. So the other methods except the first one (with -p option) will Print out Found for bash built-in commands which are not in any path in environment PATH variable.
命令和帮助是bash内置的，它们不在路径环境变量中的任何路径中。因此，除了第一个方法(带有-p选项)之外的其他方法将输出bash内置命令，这些命令在环境路径变量的任何路径中都没有。
Better use the first method (with -p option) if you only want to check if it's located in the paths in PATH environment variable.
如果您只想检查它是否位于PATH环境变量中的路径，最好使用第一个方法(带有-p选项)。
Or if you want to use type -t then change the if statement like this:
或者如果你想使用-t类型，那么改变if语句如下:
if [[ $(type -t command) == file ]]; then
#2
0
Do you mean looking at your path? Similar to:
你是说看着你的路吗?类似于:
$ set | grep PATH
Oh, now I understand. Checking for an executable in the path is fairly easy. I usually use something like the following:
哦,现在我明白了。检查路径中的可执行文件相当容易。我通常使用如下内容:
## test for exe in PATH or exit
exevar="$(which exe 2>/dev/null)"
[ x = x$exevar ] && { echo "'exe' not in path"; exit 1; }
## exe in path, continue
echo "exevar = $exevar"
or use type -p to eliminate the call to which
或者使用-p类型消除对which的调用
## test for exe in PATH or exit
exevar="$(type -p exe 2>/dev/null)"
[ x = x$exevar ] && { echo "'exe' not in path"; exit 1; }
## exe in path, continue
echo "exevar = $exevar"