bash - 将 grep 存储在变量中并在 bash 中执行 sed

Question

我有一个包含多个内容的文件，例如:

Create initial parsimony tree by phylogenetic likelihood library (PLL)... 0.022 seconds
Perform fast likelihood tree search using LG+I+G model...
Estimate model parameters (epsilon = 5.000)
Perform nearest neighbor interchange...
Estimate model parameters (epsilon = 1.000)
1. Initial log-likelihood: -30833.549
Optimal log-likelihood: -30833.420
Proportion of invariable sites: 0.016
Gamma shape alpha: 2.035
Parameters optimization took 1 rounds (0.226 sec)
Time for fast ML tree search: 2.912 seconds
NOTE: ModelFinder requires 64 MB RAM!
ModelFinder will test up to 546 protein models (sample size: 1544) ...
 No. Model         -LnL         df  AIC          AICc         BIC
  1  LG            31317.712    31  62697.424    62698.736    62863.030
  2  LG+I          31170.012    32  62404.024    62405.422    62574.972
  3  LG+G4         30870.402    32  61804.803    61806.201    61975.751
  4  LG+I+G4       30833.404    33  61732.808    61734.294    61909.098
  5  LG+R2         30881.301    33  61828.602    61830.088    62004.892
  6  LG+R3         30831.187    35  61732.374    61734.045    61919.349
Akaike Information Criterion:           VT+F+R4
Corrected Akaike Information Criterion: VT+F+R4
Bayesian Information Criterion:         VT+F+R4
Best-fit model: VT+F+R4 chosen according to BIC
other content....

我想使用 bash 命令存储该部分之后的元素:

Bayesian Information Criterion:

在名为:The_variable 的变量内。

到目前为止我尝试过:

The_variable="$(grep 'Bayesian Information Criterion:' the_file.txt)"

这给了我所有的 grep 行

echo $The_variable
Bayesian Information Criterion: VT+F+R4

但我希望它只存储 VT+F+R4 部分。

为了隔离我尝试过的部分:

sed 's@.*: @@g' $VAR

有什么想法吗？

Answer 1

使用 awk 更容易:

awk -F ' *: *' '$1 == "Bayesian Information Criterion" {print $2}' file

VT+F+R4

# to save this in a variable:
myvar=$(awk -F ' *: *' '$1 == "Bayesian Information Criterion" {print $2}' file)

此 gnu-grep 解决方案也适用于 \K:

grep -oP 'Bayesian Information Criterion:\h*\K.+' file

VT+F+R4

或者这个sed:

sed -n 's/Bayesian Information Criterion: *//p' file

VT+F+R4