Linux nlコマンドの使い方

HowtoForgeに3月7日(米国時間)に掲載された記事「Linux nl Command Tutorial for Beginners (7 Examples)」が、nlコマンドの使い方を伝えた。nlコマンドはテキストデータに行数を付与するコマンド。オプションで、空行の扱いや始まりの行数、増加数など、挙動を変更することができる。

紹介されている主な使い方は次のとおり。

nlコマンドの基本的な使い方（空行には行番号がつかない）

# nl /etc/libaudit.conf
     1  # This is the configuration file for libaudit tunables.
     2  # It is currently only used for the failure_action tunable.

     3  # failure_action can be: log, ignore, terminate
     4  failure_action = ignore


#

-b aで空行にも行番号を付ける

# nl -b a /etc/libaudit.conf
     1  # This is the configuration file for libaudit tunables.
     2  # It is currently only used for the failure_action tunable.
     3
     4  # failure_action can be: log, ignore, terminate
     5  failure_action = ignore
     6
     7
#

-iでインクリメント行数を指定

# nl -i 10 /etc/libaudit.conf
     1  # This is the configuration file for libaudit tunables.
    11  # It is currently only used for the failure_action tunable.

    21  # failure_action can be: log, ignore, terminate
    31  failure_action = ignore


#

-lで指定した連続した空行数を1つの行として扱う

# nl -b a -l 2 /etc/libaudit.conf
     1  # This is the configuration file for libaudit tunables.
     2  # It is currently only used for the failure_action tunable.

     3  # failure_action can be: log, ignore, terminate
     4  failure_action = ignore

     5
#

-nで行番号表示形式を指定。lnで左そろえ、rnで右そろえ、rzでゼロパティング出力

# nl -n ln /etc/libaudit.conf
1       # This is the configuration file for libaudit tunables.
2       # It is currently only used for the failure_action tunable.

3       # failure_action can be: log, ignore, terminate
4       failure_action = ignore


# nl -n rn /etc/libaudit.conf
     1  # This is the configuration file for libaudit tunables.
     2  # It is currently only used for the failure_action tunable.

     3  # failure_action can be: log, ignore, terminate
     4  failure_action = ignore


# nl -n rz /etc/libaudit.conf
000001  # This is the configuration file for libaudit tunables.
000002  # It is currently only used for the failure_action tunable.

000003  # failure_action can be: log, ignore, terminate
000004  failure_action = ignore


#

-sでセパレータをタブから指定した文字列へ変更

# nl -s ' [===] ' /etc/libaudit.conf
     1 [===] # This is the configuration file for libaudit tunables.
     2 [===] # It is currently only used for the failure_action tunable.

     3 [===] # failure_action can be: log, ignore, terminate
     4 [===] failure_action = ignore


#

-vで開始行数を指定

# nl -v 10 /etc/libaudit.conf
    10  # This is the configuration file for libaudit tunables.
    11  # It is currently only used for the failure_action tunable.

    12  # failure_action can be: log, ignore, terminate
    13  failure_action = ignore


#