例如，在编辑配置文件时，/etc/sysctl.conf以幂等方式进行更新通常很有用，这意味着如果多次执行脚本，您不会为所做的配置更改获得多个条目。
作为我遇到这种情况的真实实例，我需要在多阶段ansible剧本中编辑上述文件。但问题是，如果后期失败，则需要重新运行playbook，这意味着更新命令可能会运行多次，如果更新不是幂等的，则会导致重复。
那么问题是如何以幂等方式更新此类配置文件？
非幂等更新的一个示例是：
echo "vm.swappiness=10" | sudo tee -a /etc/sysctl.conf
或在 ansible 中：
- name: Set swappiness setting
shell: echo "vm.swappiness=10" | sudo tee -a /etc/sysctl.conf
理想情况下，如果最初设置了变量的值，则应将其替换为新值。
我正在遵循一个在启动时自动解密硬盘驱动器的指南，使用自生成的密钥和 tpm2 变量，接近尾声时，它使这一点似乎有意义：https: //blastrock.github.io/fde- tpm-sb.html#disable-the-magic-sysrq-key
神奇的 SysRq 键允许运行一些特殊的内核操作。默认情况下，最危险的功能是禁用的，您应该保持这种状态以获得最大的安全性。
例如，其中之一 (f) 将调用 OOM-killer。此功能可能会杀死您的锁屏，从而使恶意用户能够完全访问您的桌面。
问题是我只找到了如何禁用所有sysrq 键，例如https://askubuntu.com/questions/911522/how-can-i-enable-the-magic-sysrq-key-on-ubuntu-desktop或https ://askubuntu.com/questions/11002/alt-sysrq-reisub-doesnt-reboot-my-laptop，使用添加/etc/sysctl.d/90-sysrq.conf以下行的文件：
kernel.sysrq=1
我希望如果可能的话能够使用所有其他键，例如 REISUB，以防系统崩溃，并且只禁用该F键。
我还发现这篇文章https://www.kernel.org/doc/html/latest/admin-guide/sysrq.html，其中提到添加一个位掩码，例如：
2 = 0x2 - enable control of console logging level
4 = 0x4 - enable control of keyboard (SAK, unraw)
8 = 0x8 - enable debugging dumps of processes etc.
16 = 0x10 - enable sync command
32 = 0x20 - enable remount read-only
64 = 0x40 - enable signalling of processes (term, kill, oom-kill)
128 = 0x80 - allow reboot/poweroff
256 = 0x100 - allow nicing of all RT tasks
但我不明白如何仅禁用 sysrq-f，而将所有其他键设置为其默认值。
我的笔记本电脑（debian 12）上的当前设置如下：
$ grep -IirF sysrq /etc/sysctl.*
/etc/sysctl.conf:# 0=disable, 1=enable all, >1 bitmask of sysrq functions
/etc/sysctl.conf:# See https://www.kernel.org/doc/html/latest/admin-guide/sysrq.html
/etc/sysctl.conf:#kernel.sysrq=438
$ grep -IirF sysrq /etc/sysctl.d/*
/etc/sysctl.d/99-sysctl.conf:# 0=disable, 1=enable all, >1 bitmask of sysrq functions
/etc/sysctl.d/99-sysctl.conf:# See https://www.kernel.org/doc/html/latest/admin-guide/sysrq.html
/etc/sysctl.d/99-sysctl.conf:#kernel.sysrq=438
当路径太长而无法在终端上容纳并换行时，以下提示将被破坏，您无法正确看到键入的内容。请看下面的截图：
这些是该.bashrc设置的内容PS1，这是 Ubuntu 提供的默认设置。
if [ "$color_prompt" = yes ]; then
PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
else
PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
fi
unset color_prompt force_color_prompt
# If this is an xterm set the title to user@host:dir
case "$TERM" in
xterm*|rxvt*)
PS1="\[\e]0;${debian_chroot:+($debian_chroot)}\u@\h: \w\a\]$PS1"
;;
*)
;;
esac
的$PS1值为
echo "$PS1"
\[\e]0;\u@\h: \w\a\]${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$
有什么办法可以解决吗？
我已经看到了其他几个类似的问题，建议的解决方案是将有问题的部分包含在\[ \]或 setcheckwinsize中，但在我的情况下都不起作用。
如果有人想使用路径进行测试，则如下：
/home/dimitriv/Dropbox/personal/kastoria/2018-2019/προγραμματισμός στο διαδίκτυο/newslides
我有以下脚本来监视一些正在运行的进程：
$ cat ./print_running.sh
#!/bin/bash
ps aux | grep 'python energydata.py' | sed -r 's/\{"spectral": 0//;s/, "pp_enable.*y": 0.9,//;s/ "consumer.*ressure": 0.15,//; s/ "gamma.*//'
当我从终端运行它时，我得到如下输出：
user 27994 37.6 1.0 706712 125148 pts/19 R 15:46 0:46 python energydata.py , "l_max": 0.25 "level_flexibility": 5, "pi": 0.6489865, "z_input": 0.4450386,
user 28138 37.9 1.0 706716 124852 pts/19 R 15:47 0:32 python energydata.py , "l_max": 0.75 "level_flexibility": 5, "pi": 0.3928358, "z_input": 0.4836933,
user 28255 38.2 1.0 706716 125004 pts/19 R 15:47 0:12 python energydata.py , "l_max": 0.5 "level_flexibility": 5, "pi": 0.4088101, "z_input": 0.5011101,
user 28267 38.5 1.0 706712 125152 pts/19 R 15:47 0:13 python energydata.py , "l_max": 0.75 "level_flexibility": 5, "pi": 0.5223562, "z_input": 0.4416432,
user 28287 39.3 1.0 706712 125084 pts/19 R 15:48 0:10 python energydata.py , "l_max": 0.5 "level_flexibility": 5, "pi": 0.1073945, "z_input": 0.6377535,
user 28291 39.1 1.0 706708 124824 pts/19 R 15:48 0:10 python energydata.py , "l_max": 0.5 "level_flexibility": 5, "pi": -0.0572559, "z_input": 0.746638,
user 28305 38.9 1.0 706708 124812 pts/19 R 15:48 0:07 python energydata.py , "l_max": 0.5 "level_flexibility": 5, "pi": 0.2459162, "z_input": 0.5575399,
user 28328 38.9 1.0 706716 124836 pts/19 R 15:48 0:03 python energydata.py , "l_max": 0.5 "level_flexibility": 5, "pi": 0.7709965, "z_input": 0.3985181,
user 28329 41.1 1.0 706712 125020 pts/19 R 15:48 0:04 python energydata.py , "l_max": 0.75 "level_flexibility": 5, "pi": 0.6900067, "z_input": 0.3973544,
user 28365 0.0 0.0 14232 1092 pts/2 S+ 15:48 0:00 grep python energydata.py
但是当我通过运行命令watch来实时监控输出时，sed 过滤器似乎无法正常工作。输出如下：
$ watch ./print_running.sh
user 28427 38.2 1.0 706712 125128 pts/19 R 15:49 0:38 python energydata.py , "l_max": 0.75, "pp_enable": 0.0, "number_of_runs": 1, "profit": 0.0, "consumers_data": {"24": [[63,
user 28445 37.7 1.0 706716 124844 pts/19 R 15:49 0:35 python energydata.py , "l_max": 0.5, "pp_enable": 0.0, "number_of_runs": 1, "profit": 0.0, "consumers_data": {"24": [[63, 7
user 28511 38.0 1.0 706712 124820 pts/19 R 15:50 0:18 python energydata.py , "l_max": 0.5, "pp_enable": 0.0, "number_of_runs": 1, "profit": 0.0, "consumers_data": {"24": [[63, 7
user 28519 38.5 1.0 706716 124528 pts/19 R 15:50 0:18 python energydata.py , "l_max": 0.75, "pp_enable": 0.0, "number_of_runs": 1, "profit": 0.0, "consumers_data": {"24": [[63,
user 28533 39.2 1.0 706712 125348 pts/19 R 15:50 0:15 python energydata.py , "l_max": 0.5, "pp_enable": 0.0, "number_of_runs": 1, "profit": 0.0, "consumers_data": {"24": [[63, 7
user 28546 38.0 1.0 706708 125392 pts/19 R 15:50 0:14 python energydata.py , "l_max": 0.5, "pp_enable": 0.0, "number_of_runs": 1, "profit": 0.0, "consumers_data": {"24": [[63, 7
user 28576 38.4 1.0 706716 125100 pts/19 R 15:50 0:09 python energydata.py , "l_max": 0.5, "pp_enable": 0.0, "number_of_runs": 1, "profit": 0.0, "consumers_data": {"24": [[63, 7
user 28605 39.4 1.0 706712 125152 pts/19 R 15:50 0:07 python energydata.py , "l_max": 0.75, "pp_enable": 0.0, "number_of_runs": 1, "profit": 0.0, "consumers_data": {"24": [[63,
user 28609 37.4 1.0 706716 124868 pts/19 R 15:50 0:07 python energydata.py , "l_max": 0.5, "pp_enable": 0.0, "number_of_runs": 1, "profit": 0.0, "consumers_data": {"24": [[63, 7
user 28675 40.2 1.0 706456 124760 pts/19 R 15:50 0:01 python energydata.py , "l_max": 0.25, "pp_enable": 0.0, "number_of_runs": 1, "profit": 0.0, "consumers_data": {"24": [[63,
user 28689 0.0 0.0 14232 972 pts/2 S+ 15:50 0:00 grep python energydata.py
问题是当使用watch参数列表时没有出现过滤，所以我无法监控我感兴趣的参数。
问题：
watch？更新：
没有 sed 命令的完整输出ps aux如下所示：
user 32381 24.5 0.7 523028 90816 pts/19 R 16:19 0:00 python energydata.py {"spectral": 0, "l_max": 0.75, "pp_enable": 0.0, "number_of_runs": 1, "profit": 0.0, "consumers_data": {"24": [[63, 73]], "25": [[64, 74]], "26": [[65, 75]], "27": [[66, 76]], "20": [[59, 69]], "21": [[60, 70]], "22": [[61, 71]], "23": [[62, 72]], "28": [[67, 77]], "29": [[68, 78]], "4": [[43, 53]], "8": [[47, 57]], "59": [[66, 76]], "58": [[65, 75]], "55": [[62, 72]], "54": [[61, 71]], "57": [[64, 74]], "56": [[63, 73]], "51": [[58, 68]], "50": [[57, 67]], "53": [[60, 70]], "52": [[59, 69]], "88": [[64, 74]], "89": [[65, 75]], "82": [[57, 67]], "83": [[58, 68]], "80": [[55, 65]], "81": [[56, 66]], "86": [[61, 71]], "87": [[63, 73]], "84": [[59, 69]], "85": [[60, 70]], "3": [[42, 52]], "7": [[46, 56]], "100": [[62, 72]], "39": [[46, 56]], "38": [[45, 55]], "33": [[40, 50]], "32": [[71, 81]], "31": [[70, 80]], "30": [[69, 79]], "37": [[44, 54]], "36": [[43, 53]], "35": [[42, 52]], "34": [[41, 51]], "60": [[67, 77]], "61": [[68, 78]], "62": [[69, 79]], "63": [[70, 80]], "64": [[71, 81]], "65": [[40, 50]], "66": [[41, 51]], "67": [[42, 52]], "68": [[43, 53]], "69": [[44, 54]], "2": [[41, 51]], "6": [[45, 55]], "99": [[43, 53]], "98": [[42, 52]], "91": [[67, 77]], "90": [[66, 76]], "93": [[69, 79]], "92": [[68, 78]], "95": [[71, 81]], "94": [[70, 80]], "97": [[41, 51]], "96": [[40, 50]], "11": [[50, 60]], "10": [[49, 59]], "13": [[52, 62]], "12": [[51, 61]], "15": [[54, 64]], "14": [[53, 63]], "17": [[56, 66]], "16": [[55, 65]], "19": [[58, 68]], "18": [[57, 67]], "48": [[55, 65]], "49": [[56, 66]], "46": [[53, 63]], "47": [[54, 64]], "44": [[51, 61]], "45": [[52, 62]], "42": [[49, 59]], "43": [[50, 60]], "40": [[47, 57]], "41": [[48, 58]], "1": [[40, 50]], "5": [[44, 54]], "9": [[48, 58]], "77": [[52, 62]], "76": [[51, 61]], "75": [[50, 60]], "74": [[49, 59]], "73": [[48, 58]], "72": [[47, 57]], "71": [[46, 56]], "70": [[45, 55]], "79": [[54, 64]], "78": [[53, 63]]}, "weight_flexibility": 0.9, "level_flexibility": 5, "consumer_ids": ["100", "99", "98", "97", "96", "95", "94", "93", "92", "91", "90", "89", "88", "87", "86", "85", "84", "83", "82", "81", "80", "79", "78", "77", "76", "75", "74", "73", "72", "71", "70", "69", "68", "67", "66", "65", "64", "63", "62", "61", "60", "59", "58", "57", "56", "55", "54", "53", "52", "51", "50", "49", "48", "47", "46", "45", "44", "43", "42", "41", "40", "39", "38", "37", "36", "35", "34", "33", "32", "31", "30", "29", "28", "27", "26", "25", "24", "23", "22", "21", "20", "19", "18", "17", "16", "15", "14", "13", "12", "11", "10", "9", "8", "7", "6", "5", "4", "3", "2", "1"], "weight_friendship": 0.1, "select_algorithm": [4], "number_of_clusters": 100, "max_pressure": 0.15, "pi": 0.3606668, "z_input": 0.4976814, "gamma": 1.0, "cost": 0.02} 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