英文:
Bash egrep confusion?
问题
目前正在尝试编写一个Bash脚本，该脚本将搜索我的metar.txt文件中的变量并显示它们。我不太确定我现在在做什么。大部分脚本都是由我的老师预先制作的示例（他从未真正解释过大部分内容，或者我们没有关于它的信息）。到目前为止，我所做的是visib=$( egrep -o '\s[0-9]{2}\s' metar.txt | cut -c2-3)这一行。我认为我走在正确的道路上，但我一直得到一个输出为0。我想要从metar.txt中的1SM中提取1作为结果。我不太确定接下来该怎么做，是语法有问题还是我写错了。我正在寻求任何帮助或指向正确方向的建议。谢谢。
在我的metar.txt文件中的文本：
METAR KABC 121755Z AUTO 21016G24KT 180V240 1SM R11/P6000FT -RA BR BKN015 0VC025 06/04 A2990
Bash脚本：
#!/bin/bashprintf "Report type: "egrep -o 'METAR|SPECI' metar.txtprintf "Location: "egrep -o '\sK[A-Z]{3}\s' metar.txt#day=$( egrep -o '\s[0-9]{6}Z\s' metar.txt | cut -c2-3 )hour=$( egrep -o '\s[0-9]{6}Z\s' metar.txt | cut -c4-5 )minute=$( egrep -o '\s[0-9]{6}Z\s' metar.txt | cut -c6-7 )printf "Day of the month: %d\n" $dayprintf "Time: %d:%d Zulu" $hour $minute#windDir=$( egrep -o '\s[0-9]{5}(G[0-9]{2})?KT\s' metar.txt | cut -c2-4 )windSpd=$( egrep -o '\s[0-9]{5}(G[0-9]{2})?KT\s' metar.txt | cut -c5-6 )printf "\nWinds are from %d degrees at %d Knots" $windDir $windSpd#gustFlag=$( egrep -o '\s[0-9]{5}(G[0-9]{2})?KT\s' metar.txt | cut -c7-7 )if [ "$gustFlag" = "G" ]; thengustSpd=$( egrep -o '\s[0-9]{5}(G[0-9]{2})?KT\s' metar.txt | cut -c8-9 )printf "\nWinds are gusting at %d Knots" $gustSpdfi#varWinds=$( egrep -o '\s[0-9]{3}V[0-9]{3}\s' metar.txt )if [ -n "$varWinds" ]; thendir1=$( egrep -o '\s[0-9]{3}V[0-9]{3}\s' metar.txt | cut -c2-4)dir2=$( egrep -o '\s[0-9]{3}V[0-9]{3}\s' metar.txt | cut -c6-8)printf "\nWinds are variable from %s degrees to %s degrees" $dir1 $dir2fi#visib=$( egrep -o '\s[0-9]{2}\s' metar.txt | cut -c2-3)printf "\nVisibility: %d Statute Miles" $visib
我的输出一直是0，我试图让egrep命令从metar.txt文件中提取1SM中的1。
英文:
Currently trying to write a bash script that will search my metar.txt file for the variables and display them. I'm not really sure what I am doing currently. Most of all the script was a sample pre-made by my teacher (he really never explained most of this or we have info on it). So far what I've done though is the visib=$( egrep -o '\s[0-9]{2}\s' metar.txt | cut -c2-3)line. I think, I'm on the right path but I keep getting a output for 0. While I'm trying to get the 1SM in the metar.txt to pull the 1 as the result. I'm not really sure what to do next, if its my syntax or I have written it wrong. Any help or a point in the right direction is what, I'm looking for. Thanks.
Text in my metar.txt file
METAR KABC 121755Z AUTO 21016G24KT 180V240 1SM R11/P6000FT -RA BR BKN015 0VC025 06/04 A2990
bash plane script
#!/bin/bashprintf "Report type: "egrep -o 'METAR|SPECI' metar.txtprintf "Location: "egrep -o '\sK[A-Z]{3}\s' metar.txt#day=$( egrep -o '\s[0-9]{6}Z\s' metar.txt | cut -c2-3 )hour=$( egrep -o '\s[0-9]{6}Z\s' metar.txt | cut -c4-5 )minute=$( egrep -o '\s[0-9]{6}Z\s' metar.txt | cut -c6-7 )printf "Day of the month: %d\n" $dayprintf "Time: %d:%d Zulu" $hour $minute#windDir=$( egrep -o '\s[0-9]{5}(G[0-9]{2})?KT\s' metar.txt | cut -c2-4 )windSpd=$( egrep -o '\s[0-9]{5}(G[0-9]{2})?KT\s' metar.txt | cut -c5-6 )printf "\nWinds are from %d degrees at %d Knots" $windDir $windSpd#gustFlag=$( egrep -o '\s[0-9]{5}(G[0-9]{2})?KT\s' metar.txt | cut -c7-7 )if [ "$gustFlag" = "G" ]; thengustSpd=$( egrep -o '\s[0-9]{5}(G[0-9]{2})?KT\s' metar.txt | cut -c8-9 )printf "\nWinds are gusting at %d Knots" $gustSpdfi#varWinds=$( egrep -o '\s[0-9]{3}V[0-9]{3}\s' metar.txt )if [ -n "$varWinds" ]; thendir1=$( egrep -o '\s[0-9]{3}V[0-9]{3}\s' metar.txt | cut -c2-4)dir2=$( egrep -o '\s[0-9]{3}V[0-9]{3}\s' metar.txt | cut -c6-8)printf "\nWinds are variable from %s degrees to %s degrees" $dir1 $dir2fi#visib=$( egrep -o '\s[0-9]{2}\s' metar.txt | cut -c2-3)printf "\nVisibility: %d Statute Miles" $visib
Current Visibility outputing 0
My ouput keeps computing 0 and I'm trying to get the egrep command to pull the 1 for 1SM in the metar.txt file.
答案1
得分: 0
请标记为"已回答"如果这回答了您的问题。谢谢！
编辑 - 我查了一下规范，意识到SM可能有更多的数字，所以我修复它以允许更多。
这应该有所帮助：
visib=$(egrep -o 's[0-9]*SM' metar.txt)# 这会去掉末尾的"SM"部分visib="${visib//SM}"# 打印它...printf "\nVisibility: %d Statute Miles\n" $visib
输出：
# 用内容填充文件$ echo "METAR KABC 121755Z AUTO 21016G24KT 180V240 1SM R11/P6000FT -RA BR BKN015 0VC025 06/04 A2990" > metar.txt# 提取可见度部分$ visib=$(egrep -o 's[0-9]*SM' metar.txt)# 去掉单位visib=${visib//SM}# 打印结果$ printf "\nVisibility: %d Statute Miles\n" "$visib"Visibility: 1 Statute Miles
您也可以像这样删除单位：
$ egrep -o 's[0-9]*SM' metar.txt13SM$ egrep -o 's[0-9]*SM' metar.txt | tr -d 'SM'13$ egrep -o 's[0-9]*SM' metar.txt | tr -d '[A-Z]'13
tr是"translate"的缩写，-d表示删除提供的字符（查看man tr获取更多信息）。
英文:
Please select answered if this answered your question. Thanks!
Edit - I looked up the spec and realized there could be more numbers for SM so I fixed it to allow more.
This should help:
visib=$(egrep -o '\s[0-9]*SM' metar.txt)# this strips the "SM" part off the endvisib="${visib//SM}"# print it...printf "\nVisibility: %d Statute Miles\n" $visib
Output:
# populate file with content$ echo "METAR KABC 121755Z AUTO 21016G24KT 180V240 1SM R11/P6000FT -RA BR BKN015 0VC025 06/04 A2990" > metar.txt# extract the visibility part$ visib=$(egrep -o '\s[0-9]*SM' metar.txt)# strip off the unitsvisib=${visib//SM}# print results$ printf "\nVisibility: %d Statute Miles\n" "$visib"Visibility: 1 Statute Miles
You can also do something like this to delete the units:
$ egrep -o '\s[0-9]*SM' metar.txt13SM$ egrep -o '\s[0-9]*SM' metar.txt | tr -d 'SM'13$ egrep -o '\s[0-9]*SM' metar.txt | tr -d '[A-Z]'13
tr is "translate" and -d means delete the characters provided (type man tr for more).
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