Added getline(3), getdelim(3), sortix_gets(3) and gets(3).

gets(3) exists and is an alias for sortix_gets(3) if _SORTIX_SOURCE.

sortix_gets(3) returns a pointer to a safe newly read and allocated line.

libmaxsi/include/features.h

@@ -45,6 +45,15 @@
 	#define _SORTIX_SOURCE 1
 #endif
 
+/* Whether to override some "standard" functions with Sortix alternatives. */
+#if !defined(__SORTIX_STDLIB_REDIRECTS)
+	#if defined(_SORTIX_SOURCE)
+		#define __SORTIX_STDLIB_REDIRECTS 1
+	#else
+		#define __SORTIX_STDLIB_REDIRECTS 0
+	#endif
+#endif
+
 #define restrict
 
 /* TODO: Improve these declarations, perhaps like they are in glibc. */

libmaxsi/include/stdio.h

@@ -94,13 +94,18 @@ extern off_t ftello(FILE* stream);
 extern size_t fwrite(const void* restrict ptr, size_t size, size_t nitems, FILE* restrict stream);
 extern int getc(FILE* stream);
 extern int getchar(void);
+extern ssize_t getdelim(char** restrict lineptr, size_t* restrict n, int delimiter, FILE* restrict stream);
+extern ssize_t getline(char** restrict lineptr, size_t* restrict n, FILE* restrict stream);
 extern void perror(const char* s);
 extern int printf(const char* restrict format, ...);
 extern int putc(int c, FILE* stream);
 extern int putchar(int c);
+extern int puts(const char* str);
 extern int remove(const char* path);
 extern void rewind(FILE* stream);
 extern int snprintf(char* restrict s, size_t n, const char* restrict format, ...);
+extern char* sortix_gets(void);
+extern int sortix_puts(const char* str);
 extern int sprintf(char* restrict s, const char* restrict format, ...);
 extern int vfprintf(FILE* restrict stream, const char* restrict format, va_list ap);
 extern int vprintf(const char* restrict format, va_list ap);
@@ -127,7 +132,6 @@ extern int getc_unlocked(FILE* stream);
 extern int pclose(FILE* steam);
 extern int putchar_unlocked(int c);
 extern int putc_unlocked(int c, FILE* steam);
-extern int puts(const char* s);
 extern int rename(const char* oldname, const char* newname);
 extern int renameat(int oldfd, const char* oldname, int newfd, const char* newname);
 extern int scanf(const char* restrict format, ...);
@@ -138,14 +142,11 @@ extern int vdprintf(int fildes, const char* restrict format, va_list ap);
 extern int vfscanf(FILE* restrict stream, const char* restrict format, va_list arg);
 extern int vscanf(const char* restrict format, va_list arg);
 extern int vsscanf(const char* restrict s, const char* restrict format, va_list arg);
-extern ssize_t getdelim(char** restrict lineptr, size_t* restrict n, int delimiter, FILE* restrict stream);
-extern ssize_t getline(char** restrict lineptr, size_t* restrict n, FILE* restrict stream);
 extern void flockfile(FILE* file);
 extern void funlockfile(FILE* file);
 extern void setbuf(FILE* restrict stream, char* restrict buf);
 
 #if __POSIX_OBSOLETE <= 200801
-extern char* gets(char* s);
 extern char* tmpnam(char* s);
 extern char* tempnam(const char* dir, const char* pfx);
 #endif
@@ -158,6 +159,12 @@ FILE* fnewfile(void);
 int fcloseall(void);
 #endif
 
+#if __SORTIX_STDLIB_REDIRECTS
+inline char* gets(void) { return sortix_gets(); }
+#else
+/* traditional gets(3) is no longer POSIX, hence removed. */
+#endif
+
 __END_DECLS
 
 #endif

libmaxsi/stdio.c

@@ -22,8 +22,11 @@
 
 ******************************************************************************/
 
+#define __SORTIX_STDLIB_REDIRECTS 0
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
+#include <errno.h>
 #include "fdio.h"
 
 FILE* stdin;
@@ -48,9 +51,54 @@ int putchar(int c)
 	return fputc(c, stdout);
 }
 
-/* This function is quite stupid because of its trailing newline that fputs(3)
-   does not have - but it's still better than gets(3). I'd have left it out if
-   various programs didn't need it. */
+ssize_t getdelim(char** lineptr, size_t* n, int delim, FILE* fp)
+{
+	if ( !lineptr || (*lineptr && !n) || !fp ) { errno = EINVAL; return -1; }
+	const size_t DEFAULT_BUFSIZE = 32UL;
+	int malloced = !*lineptr;
+	if ( malloced ) { *lineptr = (char*) malloc(DEFAULT_BUFSIZE); }
+	if ( !*lineptr ) { return -1; }
+	size_t bufsize = malloced ? DEFAULT_BUFSIZE : *n;
+	if ( n ) { *n = bufsize; }
+	ssize_t written = 0;
+	int c;
+	do
+	{
+		if ( (c = getc(fp)) == EOF ) { goto cleanup; }
+		if ( bufsize <= (size_t) written + 1UL )
+		{
+			size_t newbufsize = 2UL * bufsize;
+			char* newbuf = (char*) realloc(*lineptr, newbufsize);
+			if ( !newbuf ) { goto cleanup; }
+			bufsize = newbufsize;
+			if ( n ) { *n = bufsize; }
+			*lineptr = newbuf;
+		}
+		(*lineptr)[written++] = c;
+	} while ( c != delim );
+	(*lineptr)[written] = 0;
+	return written;
+
+cleanup:
+	free(malloced ? *lineptr : NULL);
+	return -1;
+}
+
+ssize_t getline(char** lineptr, size_t* n, FILE* fp)
+{
+	return getdelim(lineptr, n, '\n', fp);
+}
+
+char* sortix_gets(void)
+{
+	char* buf = NULL;
+	size_t n;
+	if ( getline(&buf, &n, stdin) < 0 ) { return NULL; }
+	size_t linelen = strlen(buf);
+	if ( linelen && buf[linelen-1] == '\n' ) { buf[linelen-1] = 0; }
+	return buf;
+}
+
 int puts(const char* str)
 {
 	return printf("%s\n", str) < 0 ? EOF : 1;