如何同时运行两个命令？

Question

我编写了一个shell脚本（myScript.sh），其中包含以下格式的一组命令：

command1 #first run
command1 #second run
command1 #third run

现在，我想查找每个单独的command1运行消耗的最大RAM。 我可以通过在单独的终端中运行以下命令来找到命令1消耗的最大RAM：

smem -c "command pss" | grep "command1"

为了找到分别进行第一次，第二次和第三次运行所消耗的最大RAM，我以交错方式手动在不同终端上运行了run command1和smem

command1 #terminal 1
smem -c "command pss" | grep "command1" #terminal 2 in a loop to get maximum memory
command1 #terminal 1
smem -c "command pss" | grep "command1" #terminal 2 in a loop to get maximum memory
command1 #terminal 1
smem -c "command pss" | grep "command1" #terminal 2 in a loop to get maximum memory/

有什么方法可以使用linux命令或python在单个shell脚本或程序中自动执行此过程？

Answer 1

不确定Linux，但您可以在Mac OS X下的Mac上执行此操作：

/usr/bin/time -l <command> 2>&1 | grep -i max

样本输出：

/usr/bin/time -l sleep 1 2>&1 | grep -i max
557056  maximum resident set size                 # <--- program used 557kB

或者，完整输出：

/usr/bin/time -l sleep 1
        1.00 real         0.00 user         0.00 sys
    557056  maximum resident set size
         0  average shared memory size
         0  average unshared data size
         0  average unshared stack size
       145  page reclaims
         0  page faults
         0  swaps
         0  block input operations
         0  block output operations
         0  messages sent
         0  messages received
         0  signals received
         0  voluntary context switches
         2  involuntary context switches