NAME
gets — get a
string from a stdin stream
SYNOPSIS
#include
<stdio.h>
char *gets(char *s);
DESCRIPTION
[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of IEEE Std 1003.1-2001 (“POSIX.1”) defers to the ISO C standard.
The gets () function shall read
bytes from the standard input stream,
stdin, into the
array pointed to by s, until a <newline> is read or
an end-of-file condition is encountered. Any <newline> shall be
discarded and a null byte shall be placed immediately after the last byte
read into the array.
[CX] The gets ()
function may mark the st_atime field of the file
associated with stream for update. The
st_atime field shall be marked for update by the first
successful execution of fgetc(3),
fgets(3), fread(3),
getc(3), getchar(3),
gets (), fscanf(3), or
scanf(3) using stream that returns data
not supplied by a prior call to ungetc(3).
RETURN VALUE
Upon successful completion, gets () shall
return s. If the stream is at end-of-file, the end-of-file
indicator for the stream shall be set and gets ()
shall return a null pointer. If a read error occurs, the error indicator for
the stream shall be set, gets () shall return a null
pointer, [CX] and set
errno to
indicate the error.
ERRORS
Refer to fgetc(3).
EXAMPLES
None.
APPLICATION USAGE
Reading a line that overflows the array pointed to by s results in undefined behavior. The use of fgets(3) is recommended.
Since the user cannot specify the length of the buffer passed to
gets (), use of this function is discouraged. The
length of the string read is unlimited. It is possible to overflow this
buffer in such a way as to cause applications to fail, or possible system
security violations.
It is recommended that the fgets(3) function should be used to read input lines.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
feof(3), ferror(3), fgets(3), the Base Definitions volume of IEEE Std 1003.1-2001 (“POSIX.1”), <stdio.h>
CHANGE HISTORY
First released in Issue 1. Derived from Issue 1 of the SVID.
Issue 6
Extensions beyond the ISO C standard are marked.
End of informative text. footer end