The typographical conventions listed here are for ease of reading only. Editorial inconsistencies in the use of typography are unintentional and have no normative meaning in this standard.
|
Reference |
Example |
Notes |
|---|---|---|
|
C-Language Data Structure |
aiocb |
|
|
C-Language Data Structure Member |
aio_lio_opcode |
|
|
C-Language Data Type |
long |
|
|
C-Language External Variable |
errno |
|
|
C-Language Function |
system() |
|
|
C-Language Function Argument |
arg1 |
|
|
C-Language Function Family |
exec |
|
|
C-Language Header |
<sys/stat.h> |
|
|
C-Language Keyword |
return |
|
|
C-Language Macro with Argument |
assert() |
|
|
C-Language Macro with No Argument |
INET_ADDRSTRLEN |
|
|
C-Language Preprocessing Directive |
#define |
|
|
Commands within a Utility |
a, c |
|
|
Conversion Specification, Specifier/Modifier Character |
%A, g, E |
1 |
|
Environment Variable |
PATH |
|
|
Error Number |
[EINTR] |
|
|
Example Output |
Hello, World |
|
|
Filename |
/tmp |
|
|
Literal Character |
'c', '\r', '\' |
2 |
|
Literal String |
"abcde" |
2 |
|
Optional Items in Utility Syntax |
[] |
|
|
Parameter |
<directory pathname> |
|
|
Special Character |
<newline> |
3 |
|
Symbolic Constant |
_POSIX_VDISABLE |
|
|
Symbolic Limit, Configuration Value |
{LINE_MAX} |
4 |
|
Syntax |
#include <sys/stat.h> |
|
|
User Input and Example Code |
echo Hello, World |
5 |
|
Utility Name |
awk |
|
|
Utility Operand |
file_name |
|
|
Utility Option |
-c |
|
|
Utility Option with Option-Argument |
-w width |
|
Conversion specifications, specifier characters, and modifier characters are used primarily in date-related functions and utilities and the fprintf and fscanf formatting functions.
Unless otherwise noted, the quotes shall not be used as input or output. When used in a list item, the quotes are omitted. For literal characters, '\' (or any of the other sequences such as ''' ) is the same as the C constant '\\' (or '\'' ).
The style selected for some of the special characters, such as <newline>, matches the form of the input given to the localedef utility. Generally, the characters selected for this special treatment are those that are not visually distinct, such as the control characters <tab> or <newline>.
Names surrounded by braces represent symbolic limits or configuration values which may be declared in appropriate headers by means of the C #define construct.
Brackets shown in this font, "[]" , are part of the syntax and do not indicate optional items. In syntax the '|' symbol is used to separate alternatives, and ellipses ( "..." ) are used to show that additional arguments are optional.
Shading is used to identify extensions and options; see .
Footnotes and notes within the body of the normative text are for information only (informative).
Informative sections (such as Rationale, Change History, Application Usage, and so on) are denoted by continuous shading bars in the margins.
Ranges of values are indicated with parentheses or brackets as follows:
(a,b) means the range of all values from a to b, including neither a nor b.
[a,b] means the range of all values from a to b, including a and b.
[a,b) means the range of all values from a to b, including a, but not b.
(a,b] means the range of all values from a to b, including b, but not a.