Documentation/line-range-format.adoc

_<start>_ and _<end>_ can take one of these forms:

- _<number>_
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If _<start>_ or _<end>_ is a number, it specifies an
absolute line number (lines count from 1).
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- `/<regex>/`
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This form will use the first line matching the given
POSIX _<regex>_. If _<start>_ is a regex, it will search from the end of
the previous `-L` range, if any, otherwise from the start of file.
If _<start>_ is `^/<regex>/`, it will search from the start of file.
If _<end>_ is a regex, it will search starting at the line given by
_<start>_.
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- `+<offset>` or `-<offset>`
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This is only valid for _<end>_ and will specify a number
of lines before or after the line given by _<start>_.

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If `:<funcname>` is given in place of _<start>_ and _<end>_, it is a
regular expression that denotes the range from the first funcname line
that matches _<funcname>_, up to the next funcname line. `:<funcname>`
searches from the end of the previous `-L` range, if any, otherwise
from the start of file. `^:<funcname>` searches from the start of
file. The function names are determined in the same way as `git diff`
works out patch hunk headers (see 'Defining a custom hunk-header'
in linkgit:gitattributes[5]).