10.4. std
— Standard functions¶
Source code: src/text/std.h, src/text/std.c
Test code: tst/text/std/main.c
Test coverage: src/text/std.c
Functions
-
int
std_module_init
(void)¶ Initialize the std module. This function must be called before calling any other function in this module.
The module will only be initialized once even if this function is called multiple times.
- Return
- zero(0) or negative error code.
-
ssize_t std_sprintf(char * dst_p, FAR const char * fmt_p, ...)
Format and write data to destination buffer. The buffer must be big enough to fit the formatted string. The output is null terminated.
A format specifier has this format:
%[flags][width][length]specifier
where
- flags:
0
or-
- width:
0
..127
- length:
l
for long or nothing - specifier:
c
,s
,d
,i
,u
,x
orf
- Return
- Length of the string written to the destination buffer, not inclusing the null termination, or negative error code.
- Parameters
dst_p
-Destination buffer. The formatted string is written to this buffer.
fmt_p
-Format string.
...
-Variable arguments list.
- flags:
-
ssize_t std_snprintf(char * dst_p, size_t size, FAR const char * fmt_p, ...)
Format and write data to given buffer. The output is null terminated.
- Return
- Length of the string written to the destination buffer, not inclusing the null termination, or negative error code.
- Parameters
dst_p
-Destination buffer. The formatted string is written to this buffer.
size
-Size of the destination buffer.
fmt_p
-Format string.
...
-Variable arguments list.
-
ssize_t std_vsprintf(char * dst_p, FAR const char * fmt_p, va_list * ap_p)
Format and write data to given buffer. The output is null terminated.
- Return
- Length of the string written to the destination buffer, not inclusing the null termination, or negative error code.
- Parameters
dst_p
-Destination buffer. The formatted string is written to this buffer.
fmt_p
-Format string.
ap_p
-Variable arguments list.
-
ssize_t std_vsnprintf(char * dst_p, size_t size, FAR const char * fmt_p, va_list * ap_p)
Format and write data to given buffer. The output is null terminated.
- Return
- Length of the string written to the destination buffer, not inclusing the null termination, or negative error code.
- Parameters
dst_p
-Destination buffer. The formatted string is written to this buffer.
size
-Size of the destination buffer.
fmt_p
-Format string.
ap_p
-Variable arguments list.
-
ssize_t
std_printf
(far_string_t fmt_p, ...)¶ Format and print data to standard output. The output is not null terminated.
See
std_sprintf()
for the the format string specification.- Return
- Number of characters written to standard output, or negative error code.
- Parameters
fmt_p
-Format string.
...
-Variable arguemnts list.
-
ssize_t std_vprintf(FAR const char * fmt_p, va_list * ap_p)
Format and print data to standard output. The output is not null terminated.
See
std_sprintf()
for the the format string specification.- Return
- Number of characters written to standard output, or negative error code.
- Parameters
fmt_p
-Format string.
ap_p
-Variable arguemnts list.
-
ssize_t std_fprintf(void * chan_p, FAR const char * fmt_p, ...)
Format and print data to channel. The output is not null terminated.
See
std_sprintf()
for the the format string specification.- Return
- Number of characters written to given channel, or negative error code.
- Parameters
chan_p
-Output channel.
fmt_p
-Format string.
...
-Variable arguemnts list.
-
ssize_t std_vfprintf(void * chan_p, FAR const char * fmt_p, va_list * ap_p)
Format and print data to channel. The output is not null terminated.
See
std_sprintf()
for the the format string specification.- Return
- Number of characters written to given channel, or negative error code.
- Parameters
chan_p
-Output channel.
fmt_p
-Format string.
...
-Variable arguemnts list.
-
const char *
std_strtol
(const char *str_p, long *value_p)¶ Convert string to integer.
- Return
- Pointer to the next byte or NULL on failure.
- Parameters
str_p
-Integer string.
value_p
-Integer value.
-
int std_strcpy(char * dst_p, FAR const char * src_p)
Copy string from far memory to memory.
- Return
- String length or negative error code.
- Parameters
dst_p
-Normal memory string.
src_p
-Far memory string.
-
int std_strcmp(const char * str_p, FAR const char * fstr_p)
Compare a string with a far string.
- Return
- zero(0) if match, otherwise the difference of the mismatched characters
- Parameters
str_p
-Normal memory string.
fstr_p
-Far memory string.
-
int std_strcmp_f(FAR const char * fstr0_p, FAR const char * fstr1_p)
Compare two far strings.
- Return
- zero(0) if match, otherwise the difference of the mismatched characters.
- Parameters
fstr0_p
-Far memory string.
fstr1_p
-Far memory string.
-
int std_strncmp(FAR const char * fstr_p, const char * str_p, size_t size)
Compare at most
size
bytes of one far string and one string.- Return
- zero(0) if match, otherwise the difference of the mismatched characters.
- Parameters
fstr_p
-Far memory string.
str_p
-String.
size
-Compare at most size number of bytes.
-
int std_strncmp_f(FAR const char * fstr0_p, FAR const char * fstr1_p, size_t size)
Compare at most
size
bytes of two far strings.- Return
- zero(0) if match, otherwise the difference of the mismatched characters.
- Parameters
fstr0_p
-Far memory string.
fstr1_p
-Far memory string.
size
-Compare at most size number of bytes.
-
int std_strlen(FAR const char * fstr_p)
Get the length in bytes of given far string, not including null termination.
- Return
- String length in number of bytes (not including the null termination).
- Parameters
fstr_p
-Far memory string.
-
char *
std_strip
(char *str_p, const char *strip_p)¶ Strip leading and trailing characters from a string. The characters to strip are given by
strip_p
.- Return
- Pointer to the stripped string.
- Parameters
str_p
-String to strip characters from.
strip_p
-Characters to strip or NULL for whitespace characters. Must be null-terminated.