Question

我有bash文件example.sh：

#!/bin/bash

VAR=''
# if VAR empty - run this
if [-z "${VAR}" ]; then
  # some complex formula for VAR. Output is string.
   VAR = 'blablabla'
fi

我需要在下一次运行中：

#!/bin/bash

VAR='blablabla'
# if VAR empty - run this
if [-z "${VAR}" ]; then
  # some complex formula for VAR. Output is string.
   VAR = 'blablabla'
fi

在example.sh文件中的下一次运行中的VAR varable被定义为'blablabla'。我怎么能这样做？

Answer 1

我建议传入VAR作为输入参数。

然后，您可以在其自身内递归调用脚本：

#!/bin/bash

VAR=$1
# if VAR empty - run this
if [ -z "${VAR}" ]; then
    # some complex formula for VAR. Output is string.
    VAR='blablabla'
    $0 $VAR    # recursively call script with new VAR
fi

exit 0

Answer 2

我的版本：

#!/bin/bash

VAR=
FULL_PATH_TO_SCRIPT = $( readlink -m $( type -p $0 ))
# if VAR empty - run this
if [-z "${VAR}" ]; then
    # some complex formula for VAR. Output is string.
    VAR = blablabla
    sed -i '0, /VAR=/s//VAR='${VAR}'/' $FULL_PATH_TO_SCRIPT
fi
exit 0

Answer 3

不要修改脚本本身。将必要的VAR值写入外部文件，并在脚本启动时从该文件中读取。

var_file=/var/lib/myscript/var   # Just an example; put the file where convenient
read VAR < "$var_file"
# Compute value of VAR for next time
echo "$VAR" > "$var_file"

在bash文件中替换变量的字符串

3 个答案: