将 csv 文件的第一列解析为新文件 [英] Parsing the first column of a csv file to a new file

问题描述

操作系统:OSX方法:从命令行，所以使用sed，cut，gawk，虽然最好不要安装模块.

Operating System: OSX Method: From the command line, so using sed, cut, gawk, although preferably no installing modules.

本质上，我试图获取 csv 文件的第一列并将其解析为一个新文件.

Essentially I am trying to take the first column of a csv file and parse it to a new file.

示例输入文件

EXAMPLEfoo,60,6
EXAMPLEbar,30,6
EXAMPLE1,60,3
EXAMPLE2,120,6
EXAMPLE3,60,6
EXAMPLE4,30,6

期望输出

EXAMPLEfoo 
EXAMPLEbar
EXAMPLE1
EXAMPLE2
EXAMPLE3
EXAMPLE4

所以我想要第一列.

这是我迄今为止尝试过的:

Here is what I have tried so far:

awk -F"," '{print $1}' in.csv > out.txt

awk -F"," '{for (i=2;i<=NF;i++)}' in.csv > out.txt

awk -F"," 'BEGIN { OFS="," }' '{print $1}' in.csv > out.txt

cat in.csv | cut -d , -f 1 > out.txt

似乎都不起作用，要么只打印第一行，要么根本不打印，所以我认为它无法逐行读取.

None seem to work, either they just print the first line or nothing at all, so I would assume it's failing to read line by line.

推荐答案

你的最后一个选项非常适合我:

Your last option works perfectly for me:

$ cat > in.csv  # Then pasted the example input followed by Ctrl+D:
EXAMPLEfoo,60,6
EXAMPLEbar,30,6
EXAMPLE1,60,3
EXAMPLE2,120,6
EXAMPLE3,60,6
EXAMPLE4,30,6
[Ctrl+D]
$ cat in.csv | cut -d, -f1
EXAMPLEfoo
EXAMPLEbar
EXAMPLE1
EXAMPLE2
EXAMPLE3
EXAMPLE4

也许行尾在这里咬你?如果文件具有 DOS 风格甚至旧 Mac 风格的行尾，这可能会导致奇怪的行为.尝试运行 file in.csv 并查看结果.

Maybe line endings are biting you here? If the file has DOS-style or even old-Mac-style line endings, this might cause strange behaviour. Try running file in.csv and see what it comes up with.

$ file in.unix.csv
in.unix.csv: ASCII text
$ file in.dos.csv
in.dos.csv: ASCII text, with CRLF line terminators

如果是后者，请使用dos2unix工具来转换文件.

If the latter is your situation, use the dos2unix tool to convert the file.

在 OS X 上，似乎 翻转就是你想要的.

On OS X, it seems flip is what you want.

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