How can I create an array from the first line of multiple text sources?

I have an array of paths to files which each have several lines of text. I'd like to produce an array that is populated with the first line of each file processed like so:

# this.txt first line is [Test this]

# another.txt first line is [Test another]

paths=(

  ./this/path/this.txt

  ./another/path/another.txt

)



for i in ${paths[@]}; do

  read -r line < $i

  lines+=$line

done

At most I've only gotten one value in my array. I can't seem to get the array I'm looking for out of the for loop. I've tried many variations and having a hard time figuring out where I'm going wrong.

asked 43 mins ago

dimmech

221413

add a comment |

I have an array of paths to files which each have several lines of text. I'd like to produce an array that is populated with the first line of each file processed like so:

# this.txt first line is [Test this]

# another.txt first line is [Test another]

paths=(

  ./this/path/this.txt

  ./another/path/another.txt

)



for i in ${paths[@]}; do

  read -r line < $i

  lines+=$line

done

asked 43 mins ago

dimmech

221413

add a comment |

I have an array of paths to files which each have several lines of text. I'd like to produce an array that is populated with the first line of each file processed like so:

# this.txt first line is [Test this]

# another.txt first line is [Test another]

paths=(

  ./this/path/this.txt

  ./another/path/another.txt

)



for i in ${paths[@]}; do

  read -r line < $i

  lines+=$line

done

asked 43 mins ago

dimmech

221413

I have an array of paths to files which each have several lines of text. I'd like to produce an array that is populated with the first line of each file processed like so:

# this.txt first line is [Test this]

# another.txt first line is [Test another]

paths=(

  ./this/path/this.txt

  ./another/path/another.txt

)



for i in ${paths[@]}; do

  read -r line < $i

  lines+=$line

done

bash shell-script array

asked 43 mins ago

dimmech

221413

asked 43 mins ago

dimmech

221413

asked 43 mins ago

dimmech

221413

asked 43 mins ago

dimmech

221413

asked 43 mins ago

dimmech

221413

add a comment |

1 Answer
1

active

oldest

votes

You wanted

lines+=("$line")

+=WORD is string concatenation (or addition). A compound assignment +=(...) appends the values to the array.

You probably also want to quote all your variable expansions here - the line definitely needs it if the line might contain whitespace, but you could have issues elsewhere as well.

answered 36 mins ago

Michael Homer

47.8k8126165

Thanks, it makes sense now why in some of my attempts it looked like the result was a mix of the two lines.

– dimmech
24 mins ago

add a comment |

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1 Answer
1

active

oldest

votes

1 Answer
1

active

oldest

votes

You wanted

lines+=("$line")

+=WORD is string concatenation (or addition). A compound assignment +=(...) appends the values to the array.

You probably also want to quote all your variable expansions here - the line definitely needs it if the line might contain whitespace, but you could have issues elsewhere as well.

answered 36 mins ago

Michael Homer

47.8k8126165

Thanks, it makes sense now why in some of my attempts it looked like the result was a mix of the two lines.

– dimmech
24 mins ago

add a comment |

You wanted

lines+=("$line")

+=WORD is string concatenation (or addition). A compound assignment +=(...) appends the values to the array.

You probably also want to quote all your variable expansions here - the line definitely needs it if the line might contain whitespace, but you could have issues elsewhere as well.

answered 36 mins ago

Michael Homer

47.8k8126165

Thanks, it makes sense now why in some of my attempts it looked like the result was a mix of the two lines.

– dimmech
24 mins ago

add a comment |

You wanted

lines+=("$line")

+=WORD is string concatenation (or addition). A compound assignment +=(...) appends the values to the array.

You probably also want to quote all your variable expansions here - the line definitely needs it if the line might contain whitespace, but you could have issues elsewhere as well.

answered 36 mins ago

Michael Homer

47.8k8126165

You wanted

lines+=("$line")

+=WORD is string concatenation (or addition). A compound assignment +=(...) appends the values to the array.

You probably also want to quote all your variable expansions here - the line definitely needs it if the line might contain whitespace, but you could have issues elsewhere as well.

answered 36 mins ago

Michael Homer

47.8k8126165

answered 36 mins ago

Michael Homer

47.8k8126165

answered 36 mins ago

Michael Homer

47.8k8126165

answered 36 mins ago

Michael Homer

47.8k8126165

Thanks, it makes sense now why in some of my attempts it looked like the result was a mix of the two lines.

– dimmech
24 mins ago

add a comment |

Thanks, it makes sense now why in some of my attempts it looked like the result was a mix of the two lines.

– dimmech
24 mins ago

Thanks, it makes sense now why in some of my attempts it looked like the result was a mix of the two lines.

– dimmech
24 mins ago

add a comment |

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