Import sources from 2011-03-30 iso image

1 files changed, 48 insertions, 0 deletions

diff --git a/sys/src/libstdio/tmpfile.c b/sys/src/libstdio/tmpfile.c
new file mode 100755
index 000000000..0728c3652
--- /dev/null
+++ b/sys/src/libstdio/tmpfile.c
@@ -0,0 +1,48 @@
+/*
+ * pANS stdio -- tmpfile
+ *
+ * Bug: contains a critical section.  Two executions by the same
+ * user could interleave as follows, both yielding the same file:
+ *	access fails
+ *			access fails
+ *	fopen succeeds
+ *			fopen succeeds
+ *	unlink succeeds
+ *			unlink fails
+ * As I read the pANS, this can't reasonably use tmpnam to generate
+ * the name, so that code is duplicated.
+ */
+#include "iolib.h"
+
+static char tmpsmade[FOPEN_MAX][L_tmpnam+1];
+static int ntmps = 0;
+
+static void rmtmps(void);
+
+FILE *tmpfile(void){
+	FILE *f;
+	static char name[]="/tmp/tf0000000000000";
+	char *p;
+	while(access(name, 0)==0){
+		p=name+7;
+		while(*p=='9') *p++='0';
+		if(*p=='\0') return NULL;
+		++*p;
+	}
+	f=fopen(name, "wb+");
+	if(f && ntmps<FOPEN_MAX){
+		if(ntmps==0)
+			atexit(rmtmps);
+		strcpy(tmpsmade[ntmps++], name);
+	}
+	return f;
+}
+
+static void
+rmtmps(void)
+{
+	int i;
+	
+	for(i=0; i<ntmps; i++)
+		remove(tmpsmade[i]);
+}