Question

我正在尝试使用sed：

将13替换为21

echo "for i in {1..5}; do commands for FILE13 > output_${i}; done" | sed 's/13/21/g'

我的输出如下：

for i in {1..5}; do commands for FILE21 > output_2; done

13已替换为21，但${i}已替换为2。

为什么会这样？以及如何阻止sed取代mu花括号内容？

修改

如果我的命令如下所示：

echo 'for i in {1..5}; awk'{( do commands)}' FILE13  > output_${i}; done' | sed 's/13/21/g'

我无法将双引号替换为单引号，因为我得到bash: syntax error near unexpected token（'`

是使用\来逃避大括号的唯一解决方案吗？

Answer 1

它不是替换花括号的sed，而是shell。将回显字符串的双引号更改为单引号。

比较

$ echo "for i in {1..5}; do commands for FILE13 > output_${i}; done"
for i in {1..5}; do commands for FILE13 > output_; done

$ echo 'for i in {1..5}; do commands for FILE13 > output_${i}; done'
for i in {1..5}; do commands for FILE13 > output_${i}; done

如果您回显的字符串本身包含单引号，则使用双引号并转义$或直接处理引号：

$ echo "for i in {1..5}; awk'{( do commands)}' FILE13  > output_\${i}; done"
for i in {1..5}; awk'{( do commands)}' FILE13  > output_${i}; done

$ echo 'for i in {1..5}; awk'"'"'{( do commands)}'"'"' FILE13  > output_${i}; done'
for i in {1..5}; awk'{( do commands)}' FILE13  > output_${i}; done

Answer 2

echo的参数是文字字符串吗？然后：

echo "for i in {1..5}; do commands for FILE13 > output_\${i}; done" | sed 's/13/21/g'

Answer 3

您不能在单引号字符串中嵌入单引号。尝试：

echo 'for i in {1..5}; awk'"'"'{( do commands)}'"'"' FILE13  > output_${i}; done'

sed替换替换花括号$ {i} - 如何阻止？

3 个答案: