Jq 直接替换文件上的文本(如 sed -i) [英] Jq to replace text directly on file (like sed -i)

问题描述

我有一个需要在特定条件下更新的 json 文件.

I have a json file that needs to be updated on a certain condition.

示例 json

{
   "Actions" : [
      {
         "value" : "1",
         "properties" : {
            "name" : "abc",
            "age" : "2",
            "other ": "test1"
          }
      },
      {
         "value" : "2",
         "properties" : {
            "name" : "def",
            "age" : "3",
            "other" : "test2"
          }
      }
   ]
}

我正在编写一个脚本，它利用 Jq 来匹配一个值并进行更新，如下所示

I am writing a script that makes use of Jq to match a value and update, as shown below

cat sample.json |  jq '.Actions[] | select (.properties.age == "3") .properties.other = "no-test"'

输出(打印到终端)

{
  "value": "1",
  "properties": {
    "name": "abc",
    "age": "2",
    "other ": "test1"
  }
}
{
  "value": "2",
  "properties": {
    "name": "def",
    "age": "3",
    "other": "no-test"
  }
}

虽然此命令进行了所需的更改，但它会在终端上输出整个 json，并且不会更改文件本身.

While this command makes the needed change, it outputs the entire json on the terminal and does not make change to the file itself.

请告知是否有选项让 jq 直接对文件进行更改(类似于 sed -i).

Please advise if there is an option to have jq make changes on the file directly (similar to sed -i).

推荐答案

这篇文章解决了 sed 没有等效的-i"选项的问题，特别是描述的情况:

This post addresses the question about the absence of the equivalent of sed's "-i" option, and in particular the situation described:

我有一堆文件，将每个文件写入一个单独的文件并不容易.

I have a bunch of files and writing each one to a separate file wouldn't be easy.

有多种选择，至少如果您在 Mac 或 Linux 或类似环境中工作.它们的优缺点讨论在http://backreference.org/2011/01/29/就地编辑文件/所以我将只关注三种技术:

There are several options, at least if you are working in a Mac or Linux or similar environment. Their pros and cons are discussed at http://backreference.org/2011/01/29/in-place-editing-of-files/ so I'll focus on just three techniques:

一种是简单地使用&&"大致如下:

One is simply to use "&&" along the lines of:

jq ... INPUT > INPUT.tmp && mv INPUT.tmp INPUT

另一个是使用 sponge 实用程序(GNU moreutils 的一部分):

Another is to use the sponge utility (part of GNU moreutils):

jq ... INPUT | sponge INPUT

如果有利于避免在没有更改的情况下更新文件，则第三个选项可能很有用.这是一个说明这种功能的脚本:

The third option might be useful if it is advantageous to avoid updating a file if there are no changes to it. Here is a script which illustrates such a function:

#!/bin/bash

function maybeupdate {
    local f="$1"
    cmp -s "$f" "$f.tmp"
    if [ $? = 0 ] ; then
      /bin/rm $f.tmp
    else
      /bin/mv "$f.tmp" "$f"
    fi
}

for f
do
    jq . "$f" > "$f.tmp"
    maybeupdate "$f"
done

这篇关于Jq 直接替换文件上的文本(如 sed -i)的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！