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echoping/SRC/readline.c

47 lines
926 B
C

/*
* Read a line from a descriptor. Read the line one byte at a time, looking
* for the newline. We store the newline in the buffer, then follow it with
* a null (the same as fgets(3)). We return the number of characters up to,
* but not including, the null (the same as strlen(3)). If ln == 0, we treat
* newline as an ordinary charracter.
*/
/* Stolen from Stevens' book */
#include "echoping.h"
int
readline (fd, ptr, maxlen, ln)
int fd;
char *ptr;
int maxlen;
unsigned short ln;
{
int n, rc;
char c;
for (n = 1; n < maxlen; n++)
{
if (timeout_flag)
return n;
if ((rc = read (fd, &c, 1)) == 1)
{
*ptr++ = c;
if (c == '\n' && ln == 1)
break;
}
else if (rc == 0)
{
if (n == 1)
return (0); /* EOF, no data read */
else
break; /* EOF, some data was read */
}
else
return (-1); /* error */
}
*ptr = 0;
return (n);
}