如何获取匹配的行号？

Question

我的目标是获取与 /etc/crontab 中的一行匹配的字符串的行号 ($lineof)。

给予0 8 * * * Me echo "start working please"，得到this is the line number 13 from /etc/crontab。

鉴于此文件 /tmp/crontab :

# /etc/crontab: system-wide crontab
# Unlike any other crontab you don't have to run the `crontab'
# command to install the new version when you edit this file
# and files in /etc/cron.d. These files also have username fields,
# that none of the other crontabs do.

SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

# m h dom mon dow user  command
#
0 17 * * * Me echo "end of work"
0 8 * * * Me echo "start working please"
1 3 2 4 2 Me ls -la

我目前正在做类似的事情：

cat /etc/crontab | grep -v "#" | grep "Me" > /tmp/task.cron
i=1
while read -r content
do
        line=$content
        # lineof=$LINENO
        nbline=${i}
        minute=$(echo "$line" | awk '{print }')  #0-59
        hour=$(echo "$line" | awk '{print }')    #0-23
        dom=$(echo "$line" | awk '{print }')     #1-31
        month=$(echo "$line" | awk '{print }')   #1-12
        dow=$(echo "$line" | awk '{print }')     #0-6 (0=Sunday)
        cmd=$(echo "$line" | awk '{======""; print [=11=]}')    #command
        cmd=$(echo "$cmd" | tr ' ' _)
        str=$str' '$nbline' "'$minute'" "'$hour'" "'$dom'" "'$month'" "'$dow'" "'$user'" "'$cmd'" '
        i=$(($i+1))
done < /tmp/task.cron

$nbline give me the line of the content in /tmp/task.cron

$LINENO give me the line of the current script (which execute the program)

I want $lineof give me the number of the line in /etc/crontab

Answer 1

要打印匹配的行号，请使用 grep 的 -n 选项。由于模式包含一些特殊字符，使用 -F 使它们被解释为固定字符串而不是正则表达式：

grep -Fn 'your_line' /etc/crontab

但是，由于您想打印一些消息和行号，您可能想使用 awk 代替：

awk -v line='your_line' '[=11=] == line {print "this is the line number", NR, "from", FILENAME}' /etc/crontab

测试

$ cat a
# /etc/crontab: system-wide crontab
# Unlike any other crontab you don't have to run the `crontab'
# command to install the new version when you edit this file
# and files in /etc/cron.d. These files also have username fields,
# that none of the other crontabs do.

SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

# m h dom mon dow user  command
#
0 17 * * * Me echo "end of work"
0 8 * * * Me echo "start working please"
1 3 2 4 2 Me ls -la

与awk:

$ awk -v line='0 8 * * * Me echo "start working please"' '[=13=] == line {print "this is the line number", NR, "from", FILENAME}' a
this is the line number 13 from a

与grep:

$ grep -Fn '0 8 * * * Me echo "start working please"' a13:0 8 * * * Me echo "start working please"
13:0 8 * * * Me echo "start working please"

Answer 2

我终于这样了，自己找的:

nbline=1
        while read -r content
        do
                line=$content
                if [ "${line:0:1}" != "#" ]; then #if this is not a comment
                        line=$(echo -e "$line" | grep "$user") #$line keep only lines with the $user choose
                        if [ ! -z "$line" ];then #if this is not a void $line
                                minute=$(echo -e "$line" | awk '{print }') #0-59
                                hour=$(echo -e "$line" | awk '{print }')   #0-23
                                dom=$(echo -e "$line" | awk '{print }')    #1-31
                                month=$(echo -e "$line" | awk '{print }')  #1-12
                                dow=$(echo -e "$line" | awk '{print }')    #0-6 (0=Sunday)
                                cmd=$(echo -e "$line" | awk '{======""; print [=10=]}')    #command
                                cmd=$(echo -e "$cmd" | tr ' ' _) #replace space by '_' because it's annoying later
                                str=$str' "'$nbline'" "'$minute'" "'$hour'" "'$dom'" "'$month'" "'$dow'" "'$user'" "'$cmd'" '
                        fi
                fi
                nbline=$(($nbline+1))
        done < /etc/crontab

我不需要创建其他文件并在 $nbline 中获取循环中的当前行数。并计算所有行，即使它们无效或已注释。这就是我想要的。

'#'为/etc/crontab中右边内容的行号。

Answer 3

grep --fixed-strings --line-number "${match}" | cut --delimiter=":" --fields=1

如何获取匹配的行号？

How to get the line number of a match?

bash

grep

pattern-matching

string-split

测试