Vjylku

STM32 PWM problem

Are there any spells or magic items that allow for making of ‘logic gates or wires’?

What is the reason behind this musical reference to Pinocchio in the Close Encounters main theme?

How do I add a strong "onion flavor" to the biryani (in restaurant style)?

Multiple null checks in Java 8

What is formjacking?

Is it common to refer to someone as "Prof. Dr. [LastName]"?

Can I combine Divination spells with Arcane Eye?

Was the Soviet N1 really capable of sending 9.6 GB/s of telemetry?

Why is quixotic not Quixotic (a proper adjective)?

How bad is a Computer Science course that doesn't teach Design Patterns?

Are encryption algorithms with fixed-point free permutations inherently flawed?

How do I handle a blinded enemy which wants to attack someone it's sure is there?

When distributing a Linux kernel driver as source code, what's the difference between Proprietary and GPL license?

Translation for threshold (figuratively)

Can you wish for more wishes from an Efreeti bound to service via an Efreeti Bottle?

How do I avoid the "chosen hero" feeling?

How do I write a maintainable, fast, compile-time bit-mask in C++?

Does the Resurrection spell consume material components if the target isn’t willing to be resurrected?

Boss asked me to sign a resignation paper without a date on it along with my new contract

Are all power cords made equal?

Why Is Image Exporting At Larger Dimensions Than In Illustrator File?

What does "don't have a baby" imply or mean in this sentence?

How can a kingdom keep the secret of a missing monarch from the public?

Aliased pipeline using head and cut

How to use ' in alias?Bash newline doesn't printTail multiple files and output as additional column with 'find' resultsHow to document my custom bash functions and aliases?aliasing a slightly complex script on Linux/bashHow to escape single quotes correctly creating an aliasWhy doesn't this tee with process substitution produce the 1st and chosen lines?zsh alias with linefeeds, commas and quotesUsing a bash alias or function with environment variables on multiple linesSwapping STD{OUT,ERR} in a pipeline multiple times

4

I'd like to create an alias to have a quick view of the table format files with comma separator:

alias thead='head | cut -d, -f1- | column -s, -t'

Later using it like this

thead file.csv

However, it doesn't work. What would be the correct syntax?

bash alias

share|improve this question

edited 1 hour ago

Kusalananda

131k17250409

asked 2 hours ago

Max LiMax Li

1234

New contributor

Max Li is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

add a comment | 

4

I'd like to create an alias to have a quick view of the table format files with comma separator:

alias thead='head | cut -d, -f1- | column -s, -t'

Later using it like this

thead file.csv

However, it doesn't work. What would be the correct syntax?

bash alias

share|improve this question

edited 1 hour ago

Kusalananda

131k17250409

asked 2 hours ago

Max LiMax Li

1234

New contributor

Max Li is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

add a comment | 

I'd like to create an alias to have a quick view of the table format files with comma separator:

alias thead='head | cut -d, -f1- | column -s, -t'

Later using it like this

thead file.csv

However, it doesn't work. What would be the correct syntax?

bash alias

share|improve this question

edited 1 hour ago

Kusalananda

131k17250409

asked 2 hours ago

Max LiMax Li

1234

New contributor

Max Li is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

alias thead='head | cut -d, -f1- | column -s, -t'

thead file.csv

share|improve this question

edited 1 hour ago

Kusalananda

131k17250409

asked 2 hours ago

Max LiMax Li

1234

New contributor

Max Li is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

share|improve this question

edited 1 hour ago

Kusalananda

131k17250409

asked 2 hours ago

Max LiMax Li

1234

New contributor

Max Li is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

edited 1 hour ago

Kusalananda

131k17250409

edited 1 hour ago

Kusalananda

131k17250409

asked 2 hours ago

Max LiMax Li

1234

New contributor

Max Li is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

asked 2 hours ago

Max LiMax Li

1234

2 Answers
2

active

oldest

votes

6

For anything more advanced than a simple command, use a shell function instead of an alias:

thead () {

    head "$1" | cut -d, -f1- | column -s, -t

}

This shell function would run head on its first argument, and then send the result through the pipeline (although, since the cut gets all columns due to -f 1-, this part can probably be removed; I'm leaving it in here as you had it in your original pipeline).

Or,

thead () {

    head "$2" | cut -d "$1" -f1- | column -s "$1" -t

}

... to be able to use it as

thead ',' filename

Or even, to allow for an optional delimiter (and use comma if none is given),

thead () {

    local delim=','



    if [ "$#" -gt 1 ]; then

        delim=$1

        shift

    fi



    head "$1" | cut -d "$delim" -f1- | column -s "$delim" -t

}

The function definition above could be placed wherever you usually define aliases.

---

The issue with having a pipeline in an alias is that when you use the alias with an argument, this argument would be added to the end of the pipeline, not after the first command in the pipeline.

---

The bash manual contains the sentence

For almost every purpose, aliases are superseded by shell functions.

share|improve this answer

edited 36 mins ago

answered 2 hours ago

KusalanandaKusalananda

131k17250409

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  that's good, do you know btw how can I adjust it to accept a separator as a parameter to thead?
  
  – Max Li
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @MaxLi See updated answer.
  
  – Kusalananda
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @MaxLi I noticed that the delimiter was also present in the column command and that your cut command is a no-op. I fixed delimiter for column and added a note about the cut.
  
  – Kusalananda
  32 mins ago
  

  
  
  
  

add a comment | 

4

alias expansion is just text substitution which is parsed again by the shell, so when you do:

thead file.csv

That's just replaced with:

head | cut -d, -f1- | column -s, -t file.csv

and interpreted again.

If you had written:

<file.csv thead

or

cat file.csv | thead

or

{ thead; } < file.csv

It would have worked as it would have been replaced with:

<file.csv head | cut -d, -f1- | column -s, -t

cat file.csv | head | cut -d, -f1- | column -s, -t

{ head | cut -d, -f1- | column -s, -t; } < file.csv

respectively. In any case, as @Kusalananda says, it's much better to use functions or scripts than aliases for that. Here, I'd just do:

thead() { head "$@" | cut -d, -f1- | column -s, -t; }

So you can do thead -n 12 file.csv file2.csv for instance.

share|improve this answer

answered 1 hour ago

Stéphane ChazelasStéphane Chazelas

306k57580935

add a comment | 

Your Answer

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "106"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});

Max Li is a new contributor. Be nice, and check out our Code of Conduct.

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name

Email

Required, but never shown

StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f502125%2faliased-pipeline-using-head-and-cut%23new-answer', 'question_page');
}
);

Post as a guest

Name

Email

Required, but never shown

6

For anything more advanced than a simple command, use a shell function instead of an alias:

thead () {

    head "$1" | cut -d, -f1- | column -s, -t

}

This shell function would run head on its first argument, and then send the result through the pipeline (although, since the cut gets all columns due to -f 1-, this part can probably be removed; I'm leaving it in here as you had it in your original pipeline).

Or,

thead () {

    head "$2" | cut -d "$1" -f1- | column -s "$1" -t

}

... to be able to use it as

thead ',' filename

Or even, to allow for an optional delimiter (and use comma if none is given),

thead () {

    local delim=','



    if [ "$#" -gt 1 ]; then

        delim=$1

        shift

    fi



    head "$1" | cut -d "$delim" -f1- | column -s "$delim" -t

}

The function definition above could be placed wherever you usually define aliases.

---

The issue with having a pipeline in an alias is that when you use the alias with an argument, this argument would be added to the end of the pipeline, not after the first command in the pipeline.

---

The bash manual contains the sentence

For almost every purpose, aliases are superseded by shell functions.

share|improve this answer

edited 36 mins ago

answered 2 hours ago

KusalanandaKusalananda

131k17250409

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  that's good, do you know btw how can I adjust it to accept a separator as a parameter to thead?
  
  – Max Li
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @MaxLi See updated answer.
  
  – Kusalananda
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @MaxLi I noticed that the delimiter was also present in the column command and that your cut command is a no-op. I fixed delimiter for column and added a note about the cut.
  
  – Kusalananda
  32 mins ago
  

  
  
  
  

add a comment | 

6

For anything more advanced than a simple command, use a shell function instead of an alias:

thead () {

    head "$1" | cut -d, -f1- | column -s, -t

}

This shell function would run head on its first argument, and then send the result through the pipeline (although, since the cut gets all columns due to -f 1-, this part can probably be removed; I'm leaving it in here as you had it in your original pipeline).

Or,

thead () {

    head "$2" | cut -d "$1" -f1- | column -s "$1" -t

}

... to be able to use it as

thead ',' filename

Or even, to allow for an optional delimiter (and use comma if none is given),

thead () {

    local delim=','



    if [ "$#" -gt 1 ]; then

        delim=$1

        shift

    fi



    head "$1" | cut -d "$delim" -f1- | column -s "$delim" -t

}

The function definition above could be placed wherever you usually define aliases.

---

The issue with having a pipeline in an alias is that when you use the alias with an argument, this argument would be added to the end of the pipeline, not after the first command in the pipeline.

---

The bash manual contains the sentence

For almost every purpose, aliases are superseded by shell functions.

share|improve this answer

edited 36 mins ago

answered 2 hours ago

KusalanandaKusalananda

131k17250409

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  that's good, do you know btw how can I adjust it to accept a separator as a parameter to thead?
  
  – Max Li
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @MaxLi See updated answer.
  
  – Kusalananda
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @MaxLi I noticed that the delimiter was also present in the column command and that your cut command is a no-op. I fixed delimiter for column and added a note about the cut.
  
  – Kusalananda
  32 mins ago
  

  
  
  
  

add a comment | 

For anything more advanced than a simple command, use a shell function instead of an alias:

thead () {

    head "$1" | cut -d, -f1- | column -s, -t

}

This shell function would run head on its first argument, and then send the result through the pipeline (although, since the cut gets all columns due to -f 1-, this part can probably be removed; I'm leaving it in here as you had it in your original pipeline).

Or,

thead () {

    head "$2" | cut -d "$1" -f1- | column -s "$1" -t

}

... to be able to use it as

thead ',' filename

Or even, to allow for an optional delimiter (and use comma if none is given),

thead () {

    local delim=','



    if [ "$#" -gt 1 ]; then

        delim=$1

        shift

    fi



    head "$1" | cut -d "$delim" -f1- | column -s "$delim" -t

}

The function definition above could be placed wherever you usually define aliases.

---

The issue with having a pipeline in an alias is that when you use the alias with an argument, this argument would be added to the end of the pipeline, not after the first command in the pipeline.

---

The bash manual contains the sentence

For almost every purpose, aliases are superseded by shell functions.

share|improve this answer

edited 36 mins ago

answered 2 hours ago

KusalanandaKusalananda

131k17250409

thead () {

    head "$1" | cut -d, -f1- | column -s, -t

}

thead () {

    head "$2" | cut -d "$1" -f1- | column -s "$1" -t

}

thead ',' filename

thead () {

    local delim=','



    if [ "$#" -gt 1 ]; then

        delim=$1

        shift

    fi



    head "$1" | cut -d "$delim" -f1- | column -s "$delim" -t

}

share|improve this answer

edited 36 mins ago

answered 2 hours ago

KusalanandaKusalananda

131k17250409

answered 2 hours ago

KusalanandaKusalananda

131k17250409

answered 2 hours ago

KusalanandaKusalananda

131k17250409

4

alias expansion is just text substitution which is parsed again by the shell, so when you do:

thead file.csv

That's just replaced with:

head | cut -d, -f1- | column -s, -t file.csv

and interpreted again.

If you had written:

<file.csv thead

or

cat file.csv | thead

or

{ thead; } < file.csv

It would have worked as it would have been replaced with:

<file.csv head | cut -d, -f1- | column -s, -t

cat file.csv | head | cut -d, -f1- | column -s, -t

{ head | cut -d, -f1- | column -s, -t; } < file.csv

respectively. In any case, as @Kusalananda says, it's much better to use functions or scripts than aliases for that. Here, I'd just do:

thead() { head "$@" | cut -d, -f1- | column -s, -t; }

So you can do thead -n 12 file.csv file2.csv for instance.

share|improve this answer

answered 1 hour ago

Stéphane ChazelasStéphane Chazelas

306k57580935

add a comment | 

4

alias expansion is just text substitution which is parsed again by the shell, so when you do:

thead file.csv

That's just replaced with:

head | cut -d, -f1- | column -s, -t file.csv

and interpreted again.

If you had written:

<file.csv thead

or

cat file.csv | thead

or

{ thead; } < file.csv

It would have worked as it would have been replaced with:

<file.csv head | cut -d, -f1- | column -s, -t

cat file.csv | head | cut -d, -f1- | column -s, -t

{ head | cut -d, -f1- | column -s, -t; } < file.csv

respectively. In any case, as @Kusalananda says, it's much better to use functions or scripts than aliases for that. Here, I'd just do:

thead() { head "$@" | cut -d, -f1- | column -s, -t; }

So you can do thead -n 12 file.csv file2.csv for instance.

share|improve this answer

answered 1 hour ago

Stéphane ChazelasStéphane Chazelas

306k57580935

add a comment | 

alias expansion is just text substitution which is parsed again by the shell, so when you do:

thead file.csv

That's just replaced with:

head | cut -d, -f1- | column -s, -t file.csv

and interpreted again.

If you had written:

<file.csv thead

or

cat file.csv | thead

or

{ thead; } < file.csv

It would have worked as it would have been replaced with:

<file.csv head | cut -d, -f1- | column -s, -t

cat file.csv | head | cut -d, -f1- | column -s, -t

{ head | cut -d, -f1- | column -s, -t; } < file.csv

respectively. In any case, as @Kusalananda says, it's much better to use functions or scripts than aliases for that. Here, I'd just do:

thead() { head "$@" | cut -d, -f1- | column -s, -t; }

So you can do thead -n 12 file.csv file2.csv for instance.

share|improve this answer

answered 1 hour ago

Stéphane ChazelasStéphane Chazelas

306k57580935

thead file.csv

head | cut -d, -f1- | column -s, -t file.csv

<file.csv thead

cat file.csv | thead

{ thead; } < file.csv

<file.csv head | cut -d, -f1- | column -s, -t

cat file.csv | head | cut -d, -f1- | column -s, -t

{ head | cut -d, -f1- | column -s, -t; } < file.csv

thead() { head "$@" | cut -d, -f1- | column -s, -t; }

share|improve this answer

answered 1 hour ago

Stéphane ChazelasStéphane Chazelas

306k57580935

answered 1 hour ago

Stéphane ChazelasStéphane Chazelas

306k57580935

answered 1 hour ago

Stéphane ChazelasStéphane Chazelas

306k57580935