examples.md

Format Options Examples

Table of Contents

• Preserve Formatting
  • separatorParts
  • separatorHostname
• Don't Preserve Formatting
  • separatorParts
  • separatorHostname

Preserve Formatting

preserveFormatting is true by default. The following examples show how separatorParts and separatorHostname work while preserving formatting.

separatorParts

Given an empty hosts file

await assignHostnames('1.2.3.4', ['hostname1'])
// updates it to
// 1.2.3.4{tab}hostname1

to insert a space instead of a tab for new host entries:

await assignHostnames('5.6.7.8', ['hostname2'], { separatorParts: ' ' })
// adds the line
// 5.6.7.8{space}hostname2

separatorHostname

Given a hosts file

1.2.3.4 hostname1{tab}hostname2

await assignHostnames('1.2.3.4', ['hostname3'])
// updates /etc/hosts to
// 1.2.3.4 hostname1{tab}hostname2{space}hostname3

to insert a tab instead of a space for new hostnames:

await assignHostnames('1.2.3.4', ['hostname4'], { separatorHostname: '\t' })
// updates /etc/hosts to
// 1.2.3.4 hostname1{tab}hostname2{space}hostname3{tab}hostname4

Don't Preserve Formatting

The following examples show how separatorParts and separatorHostname work when preserveFormatting is false.

Given a hosts file

1.2.3.4{space}hostname1{space}#some comment
5.6.7.8{space}hostname2

Assigning any hostname will normalize all whitespace

await assignHostnames('5.6.7.8', ['hostname3'], { preserveFormatting: false })
// updates it to
// 1.2.3.4{tab}hostname1{tab}#some comment
// 5.6.7.8{tab}hostname2{space}hostname3

If we assign an existing hostname then the file isn't touched regardless of whitespace.

Let's reset the host file to show what I mean:

1.2.3.4{space}hostname1{space}#some comment
5.6.7.8{space}hostname2

and assign an existing hostname

await assignHostnames('5.6.7.8', ['hostname2'], { preserveFormatting: false })
// doesn't modify the hosts file

separatorParts

Let's separate the parts via two spaces instead of a tab.

Given a hosts file

1.2.3.4{tab}hostname1{tab}#some comment
5.6.7.8{tab}hostname2{tab}hostname3

await assignHostnames('5.6.7.8', ['hostname4'], {
  preserveFormatting: false,
  separatorParts: spaces[2],
})
// updates it to: (hyphen represents a space)
// 1.2.3.4--hostname1--#some comment
// 5.6.7.8--hostname2-hostname3-hostname4

separatorHostname

Let's separate the hostnames by two spaces instead of one

Given a hosts file

1.2.3.4{space}hostname1{tab}hostname2

await assignHostnames('1.2.3.4', ['hostname3'], { separateHostname: spaces[2] })
// updates it to: (hyphen represents a space)
// 1.2.3.4{tab}hostname1--hostname2--hostname3