bash 在循环“~$ ./program >”时删除我的文件文件.dat” （gnuplot）
我正在 bash 上编写一些脚本，以使用 gnuplot 绘制数据。但这不起作用。
我有一个将数据发送到命令行的程序。 我将这些数据收集到一个文件中，然后循环此过程以获得所需的结果。假设我有这个脚本
N = 10
./program.exe > data_$N.dat # Creating the data to be plotted
for ((i = 0 ; i<1 ; i++)) do # Dummy loop to throw all together to gnuplot
echo "set size square"
echo "set xrange[-$N-1:$N+1]; set yrange[-$N-1:$N+1];"
echo "plot '-' using 1:2"
for((j = 0 ; j <= 9 ; j++)) do
# Throwing the data to gnuplot
echo "cat data_$N.dat"
# Updating the file and overwriting on it
echo "cat data_$N.dat | xargs ./program.exe > data_$N.dat" | bash
echo "e"
echo "pause 0.5"
done
done | gnuplot -persist # Throwing the formatted data to gnuplot
，那么，基本上我将格式化文本从文件扔到 gnuplot，更改它的内容，但不更改文件名。
当然，我不想更改文件的名称，因为我使用该文件进行与该步骤相对应的计算，然后用更新的数据覆盖该文件。一种缓冲区。计算流程将是
./program.exe > data.dat # Making the initial data
begin gnuplot loop
throw data to gnuplot
"cat data.dat | xargs ./program.exe > data.dat" # update data overwriting file
end gnuplot loop
pipe all the script to gnuplot
希望很清楚，你可以帮助我:)。谢谢！
PD。我是一名物理学家。
I'm doing some script on bash to plot data with gnuplot. But it doesn't work.
I have a program which throws data to the command line.
I collect that data on a file and then I loop this process over to get the desired result. Say I have this script
N = 10
./program.exe > data_$N.dat # Creating the data to be plotted
for ((i = 0 ; i<1 ; i++)) do # Dummy loop to throw all together to gnuplot
echo "set size square"
echo "set xrange[-$N-1:$N+1]; set yrange[-$N-1:$N+1];"
echo "plot '-' using 1:2"
for((j = 0 ; j <= 9 ; j++)) do
# Throwing the data to gnuplot
echo "cat data_$N.dat"
# Updating the file and overwriting on it
echo "cat data_$N.dat | xargs ./program.exe > data_$N.dat" | bash
echo "e"
echo "pause 0.5"
done
done | gnuplot -persist # Throwing the formatted data to gnuplot
So, basically I throw formatted text to gnuplot from a file, changing the content of it, but without changing the name of the file.
Of course, I don't wanna change the name of the file because I make the calculations corresponding to that step with that file, and then I overwrite the file with the updated data. Kind of a buffer. The computational flow would be
./program.exe > data.dat # Making the initial data
begin gnuplot loop
throw data to gnuplot
"cat data.dat | xargs ./program.exe > data.dat" # update data overwriting file
end gnuplot loop
pipe all the script to gnuplot
Hope is clear and you can help me :). Thanks!
PD. I'm a physicist.
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>的重定向是由 shell 完成的。因此，执行 cat data_$N.dat | 时发生的第一件事是xargs ./program.exe > data_$N.dat 是 shell 打开data_$N.dat进行写入并截断它。现在它是空的，所以当cat启动时它会找到一个文件，但它已经被截断了。只需将您的输出重定向到临时位置（通常在返回 PID 的位置中使用
$$，以便您的脚本在某种程度上是独立的）。所以...> tmp_$$.dat然后就可以mv -f tmp_$$.dat data_$N.dat。Redirection with
>is done by the shell. So the first thing that happens when executingcat data_$N.dat | xargs ./program.exe > data_$N.datis that the shell opensdata_$N.datfor write and truncates it. Now it's empty, so whencatstarts it finds a file but it has already been truncated.Just redirect your output to a temporary location (it's common to use
$$in that which returns your PID so your scripts are somewhat independent). So... > tmp_$$.datand then right after that you canmv -f tmp_$$.dat data_$N.dat.