Gestern habe ich noch bprintf(1) dazu gebaut. Das existiert hauptsächlich damit ich eine Manual page habe in der ich die Formatting syntax von loaderupdate -L beschreiben kann:
Code:
BPRINTF(1) FreeBSD General Commands Manual BPRINTF(1)
NAME
bprintf – formatted output with named arguments
SYNOPSIS
bprintf format [field=value ...]
DESCRIPTION
The bprintf command is an advanced string formatting utility. It is a
semantic wrapper for printf(1). bprintf replaces argument order with
named arguments and can perform arithmetic within format specifications.
A format string can contain a set of substitutions. A substitution
consists of a field name and an optional format specification. The format
specification determines how the field value is interpreted and
displayed. A single field may be used within multiple substitutions, each
with its own formatting.
Format Syntax
The format string is reproduced on stdout after performing substitutions.
The backslash notation character escape sequences supported by printf(1)
can be used. The ‘%’ character has no special meaning.
A substitution is enclosed in curly braces. To print a literal opening or
closing curly brace escape it with a backslash, i.e. ‘\{’ and ‘\}’
respectively.
A substitution consists of the field name and an optional format
specification:
{field[:specification]}
A substitution without a specification behaves like a ‘%s’ field in
printf(1).
The format specification consists of the same flags, Field Width,
Precision and Format characters described by printf(1). If the format
character is not supplied, ‘s’ is implied. An arithmetic expression can
be inserted into the format by enclosing it in parenthesis.
Arithmetic Expressions
Arithmetic expressions support the same Values, Constants and Variables
as well as the same Unary, Binary and Conditional operators as described
in the Arithmetic Expansion section of sh(1).
Note, this list does not include Assignment operators.
All variables referred to within an expression must have a corresponding
field with an integral value assigned. Variables can be assigned values
with the same syntax as constants, i.e. an optional sign followed by
either a decimal value, hexadecimal value starting with ‘0x’ or an octal
value starting with ‘0’.
Field Assignments
The format string may use all and any fields supplied by the subsequent
field=value arguments. Fields not occurring in the format string are
discarded from the output. Values are arbitrary unless used within
arithmetic expressions.
Field names must be made up of the pattern ‘[a-zA-Z][a-zA-Z0-9_]*’.
EXIT STATUS
The following is a list of all anticipated exit codes:
EOK=0 Command completed successfully.
ESIGNAL=1
Interrupted by signal.
EFAIL=2
Generic application logic error.
ENOARGS=3
No format string was supplied.
ESUB=4 A substitution field has no corresponding field assignment
argument.
EID=5 A substitution field name is illegal.
EFORMAT=6
A substitution format specification is ill-formed.
EEXPR=7
An arithmetic expression is ill-formed.
EASSIGN=8
An arithmetic expression contains an assignment.
EARG=9 An argument uses an illegal field name.
ETYPE=10
A field value used in an arithmetic expression is not an integer.
EXAMPLES
Simple substitution:
$ bprintf 'My name is {name}.\n' name=Johnny
My name is Johnny.
Using a field multiple times:
$ bprintf '{str:.5}\n{str:.10}\n{str}\n' str=SugarHoneyMilk
Sugar
SugarHoney
SugarHoneyMilk
Use different field types:
$ bprintf '{var:16} = {value:g} {unit}\n' var=g value=9.81 unit=mps^2
g = 9.81 mps^2
Compute column width using arithmetic expressions:
$ bprintf '| {name:-16} | {val:(cols-36)} {unit:-12} |\n' cols=64 name=Name val=Value unit=Unit
| Name | Value Unit |
$ bprintf '| {name:-16} | {val:(cols-36).3f} {unit:-12} |\n' cols=64 name=g val=9.81 unit=mps^2
| g | 9.810 mps^2 |
SEE ALSO
printf(1), sh(1)
HISTORY
The bprintf command was added with the bsda2-0.4.0 release.
AUTHORS
Dominic Fandrey <freebsd@k4m1.org>
FreeBSD 12.2-STABLE 19 January, 2021 FreeBSD 12.2-STABLE
