BGETS(3GEN) String Pattern-Matching Library Functions BGETS(3GEN)

NAME

bgets - read stream up to next delimiter

SYNOPSIS

cc [ flag ... ] file ... -lgen [ library ... ]
#include <libgen.h>

char *bgets(char *buffer, size_t count, FILE *stream,
const char *breakstring);

DESCRIPTION

The bgets() function reads characters from stream into buffer until
either count is exhausted or one of the characters in breakstring is
encountered in the stream. The read data is terminated with a null
byte ('\0') and a pointer to the trailing null is returned. If a
breakstring character is encountered, the last non-null is the
delimiter character that terminated the scan.


Note that, except for the fact that the returned value points to the
end of the read string rather than to the beginning, the call

bgets(buffer, sizeof buffer, stream, "\n");


is identical to

fgets (buffer, sizeof buffer, stream);


There is always enough room reserved in the buffer for the trailing
null character.


If breakstring is a null pointer, the value of breakstring from the
previous call is used. If breakstring is null at the first call, no
characters will be used to delimit the string.

RETURN VALUES

NULL is returned on error or end-of-file. Reporting the condition is
delayed to the next call if any characters were read but not yet
returned.

EXAMPLES

Example 1: Example of the bgets() function.

The following example prints the name of the first user encountered
in /etc/passwd, including a trailing ":"


#include <stdio.h>
#include <libgen.h>

int main()
{
char buffer[8];
FILE *fp;

if ((fp = fopen("/etc/passwd","r")) == NULL) {
perror("/etc/passwd");
return 1;
}
if (bgets(buffer, 8, fp, ":") == NULL) {
perror("bgets");
return 1;
}
(void) puts(buffer);
return 0;
}

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+---------------+-----------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-----------------+
|MT-Level | MT-Safe |
+---------------+-----------------+

SEE ALSO

gets(3C), attributes(7)

NOTES

When compiling multithread applications, the _REENTRANT flag must be
defined on the compile line. This flag should only be used in
multithreaded applications.

March 10, 2023 BGETS(3GEN)