我正在努力实现以下目标。
编辑前的文件。
column-1, column-2, column-3, column-4, column-5
Row-1-c1, Row-1-c2, Row-1-c3, Row-1-c4, Row-1-c5
Row-2-c1, Row-2-c2, Row-2-c3, Row-2-c4, Row-2-c5
Row-3-c1, Row-3-c2, Row-3-c3, Row-3-c4, Row-3-c5
Row-4-c1, Row-4-c2, Row-4-c3, Row-4-c4, Row-4-c5
Row-5-c1, Row-5-c2, Row-5-c3, Row-5-c4, Row-5-c5
编辑后的文件
column-1, column-2, column-3, column-4, column-5
Row-1-c1, Row-1-c2, Prefix-Row-1-c3, Row-1-c4, Row-1-c5
Row-2-c1, Row-2-c2, Prefix-Row-2-c3, Row-2-c4, Row-2-c5
Row-3-c1, Row-3-c2, Prefix-Row-3-c3, Row-3-c4, Row-3-c5
Row-4-c1, Row-4-c2, Prefix-Row-4-c3, Row-4-c4, Row-4-c5
Row-5-c1, Row-5-c2, Prefix-Row-5-c3, Row-5-c4, Row-5-c5
请注意，column-3 是为除列标题之外的每一行添加前缀的列。 我想知道哪个编辑器是最好使用的编辑器，并了解如何使用命令来获得所需的结果。
最佳答案
也许更好的问题是“您可以使用多少种不同的工具来完成这项工作？”
我可能会选择 awk 作为最简单的工具，它可以相当简单地完成这项工作:
awk -F, 'NR == 1 { print; OFS="," } NR > 1 { sub(/^ +/, "&Prefix-", $3); print }'
sub 操作在第 3 列开头的空格后面添加 Prefix-。该代码不会尝试调整第 1 行(标题)的内容；如果您想在 $3 之后添加空格，那么我想这可以完成任务(由于逗号的位置，您可以将额外的空格添加到第 1 行的第 4 列之前):
awk -F, 'NR == 1 { OFS=","; $4 = " " $4; print }
NR > 1 { sub(/^ +/, "&Prefix-", $3); print }'
Do you know how to do the same thing with sed?
是的，像这样:
sed -e ' 1s/^\(\([^,]*,[[:space:]]*\)\{3\}\)/\1 /' \
-e '2,$s/^\(\([^,]*,[[:space:]]*\)\{2\}\)/\1Prefix-/' "$@"
第一个表达式处理第一行；它在第三列之后放置与前缀中一样多的空格(这里是“Prefix-”，所以它是 7 个空格)。第二个表达式处理剩余的行；它在第三列之前添加前缀。
要处理第 N 列而不是第 3 列，请将 \{2\} 中的 3 更改为 N，将 2 更改为 N-1。
我重新检查了第二个 Awk 脚本；它根据问题的样本数据为我生成正确的输出。因此，在其限制范围内，第一个 Awk 脚本也是如此。确保您使用的是 C shell 以外的其他东西(它会被多行带引号的字符串弄乱)，并且您在复制时要小心。
输出示例
$ cat data
column-1, column-2, column-3, column-4, column-5
Row-1-c1, Row-1-c2, Row-1-c3, Row-1-c4, Row-1-c5
Row-2-c1, Row-2-c2, Row-2-c3, Row-2-c4, Row-2-c5
Row-3-c1, Row-3-c2, Row-3-c3, Row-3-c4, Row-3-c5
Row-4-c1, Row-4-c2, Row-4-c3, Row-4-c4, Row-4-c5
Row-5-c1, Row-5-c2, Row-5-c3, Row-5-c4, Row-5-c5
$ bash manglesed.sh data
column-1, column-2, column-3, column-4, column-5
Row-1-c1, Row-1-c2, Prefix-Row-1-c3, Row-1-c4, Row-1-c5
Row-2-c1, Row-2-c2, Prefix-Row-2-c3, Row-2-c4, Row-2-c5
Row-3-c1, Row-3-c2, Prefix-Row-3-c3, Row-3-c4, Row-3-c5
Row-4-c1, Row-4-c2, Prefix-Row-4-c3, Row-4-c4, Row-4-c5
Row-5-c1, Row-5-c2, Prefix-Row-5-c3, Row-5-c4, Row-5-c5
$ bash mangleawk.sh data
column-1, column-2, column-3, column-4, column-5
Row-1-c1, Row-1-c2, Prefix-Row-1-c3, Row-1-c4, Row-1-c5
Row-2-c1, Row-2-c2, Prefix-Row-2-c3, Row-2-c4, Row-2-c5
Row-3-c1, Row-3-c2, Prefix-Row-3-c3, Row-3-c4, Row-3-c5
Row-4-c1, Row-4-c2, Prefix-Row-4-c3, Row-4-c4, Row-4-c5
Row-5-c1, Row-5-c2, Prefix-Row-5-c3, Row-5-c4, Row-5-c5
$ cat manglesed.sh
sed -e ' 1s/^\(\([^,]*,[[:space:]]*\)\{3\}\)/\1 /' \
-e '2,$s/^\(\([^,]*,[[:space:]]*\)\{2\}\)/\1Prefix-/' "$@"
$ cat mangleawk.sh
awk -F, 'NR == 1 { OFS=","; $4 = " " $4; print }
NR > 1 { sub(/^ +/, "&Prefix-", $3); print }' "$@"
$ awk -F, 'NR == 1 { print; OFS="," } NR > 1 { sub(/^ +/, "&Prefix-", $3); print }' data
column-1, column-2, column-3, column-4, column-5
Row-1-c1, Row-1-c2, Prefix-Row-1-c3, Row-1-c4, Row-1-c5
Row-2-c1, Row-2-c2, Prefix-Row-2-c3, Row-2-c4, Row-2-c5
Row-3-c1, Row-3-c2, Prefix-Row-3-c3, Row-3-c4, Row-3-c5
Row-4-c1, Row-4-c2, Prefix-Row-4-c3, Row-4-c4, Row-4-c5
Row-5-c1, Row-5-c2, Prefix-Row-5-c3, Row-5-c4, Row-5-c5
$
关于csv - 如何在 Linux 上通过命令行为 CSV 文件中特定列的每一行添加前缀，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/24226003/