Changeset 11544f4 in mainline

Timestamp:

2011-07-29T17:46:54Z (13 years ago)

Author:

Jiří Zárevúcky <zarevucky.jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

2a53f71

Parents:

ffff746

Message:

Implement a few functions for dealing with temporary files.

Location:

uspace/lib/posix

Files:

• stdio.c (modified) (2 diffs)
• stdio.h (modified) (2 diffs)
• stdlib.c (modified) (2 diffs)
• stdlib.h (modified) (2 diffs)

uspace/lib/posix/stdio.c

@@ -44 +44 @@
 #include "assert.h"
 #include "errno.h"
+#include "stdlib.h"
 #include "string.h"
 #include "sys/types.h"
+#include "unistd.h"
 
 #include "libc/io/printf_core.h"
@@ -734 +736 @@
 
 /**
- * 
- * @param s
- * @return
+ * Get a unique temporary file name (obsolete).
+ *
+ * @param s Buffer for the file name. Must be at least L_tmpnam bytes long.
+ * @return The value of s on success, NULL on failure.
  */
 char *posix_tmpnam(char *s)
 {
-        // TODO: low priority, just a compile-time dependency of binutils
-        not_implemented();
+        assert(L_tmpnam >= posix_strlen("/tmp/tnXXXXXX"));
+        
+        static char buffer[L_tmpnam + 1];
+        if (s == NULL) {
+                s = buffer;
+        }
+        
+        posix_strcpy(s, "/tmp/tnXXXXXX");
+        posix_mktemp(s);
+        
+        if (*s == '\0') {
+                /* Errno set by mktemp(). */
+                return NULL;
+        }
+        
+        return s;
+}
+
+/**
+ * Get an unique temporary file name with additional constraints (obsolete).
+ *
+ * @param dir Path to directory, where the file should be created.
+ * @param pfx Optional prefix up to 5 characters long.
+ * @return Newly allocated unique path for temporary file. NULL on failure.
+ */
+char *posix_tempnam(const char *dir, const char *pfx)
+{
+        /* Sequence number of the filename. */
+        static int seq = 0;
+        
+        size_t dir_len = posix_strlen(dir);
+        if (dir[dir_len - 1] == '/') {
+                dir_len--;
+        }
+        
+        size_t pfx_len = posix_strlen(pfx);
+        if (pfx_len > 5) {
+                pfx_len = 5;
+        }
+        
+        char *result = malloc(dir_len + /* slash*/ 1 +
+            pfx_len + /* three-digit seq */ 3 + /* .tmp */ 4 + /* nul */ 1);
+        
+        if (result == NULL) {
+                errno = ENOMEM;
+                return NULL;
+        }
+        
+        char *res_ptr = result;
+        posix_strncpy(res_ptr, dir, dir_len);
+        res_ptr += dir_len;
+        posix_strncpy(res_ptr, pfx, pfx_len);
+        res_ptr += pfx_len;
+        
+        for (; seq < 1000; ++seq) {
+                snprintf(res_ptr, 8, "%03d.tmp", seq);
+                
+                int orig_errno = errno;
+                errno = 0;
+                /* Check if the file exists. */
+                if (posix_access(result, F_OK) == -1) {
+                        if (errno == ENOENT) {
+                                errno = orig_errno;
+                                break;
+                        } else {
+                                /* errno set by access() */
+                                return NULL;
+                        }
+                }
+        }
+        
+        if (seq == 1000) {
+                free(result);
+                errno = EINVAL;
+                return NULL;
+        }
+        
+        return result;
+}
+
+/**
+ * Create and open an unique temporary file.
+ * The file is automatically removed when the stream is closed.
+ *
+ * @param dir Path to directory, where the file should be created.
+ * @param pfx Optional prefix up to 5 characters long.
+ * @return Newly allocated unique path for temporary file. NULL on failure.
+ */
+FILE *posix_tmpfile(void)
+{
+        char filename[] = "/tmp/tfXXXXXX";
+        int fd = posix_mkstemp(filename);
+        if (fd == -1) {
+                /* errno set by mkstemp(). */
+                return NULL;
+        }
+        
+        /* Unlink the created file, so that it's removed on close(). */
+        posix_unlink(filename);
+        return fdopen(fd, "w+");
 }
 

uspace/lib/posix/stdio.h

@@ -123 +123 @@
 #define L_tmpnam PATH_MAX
 extern char *posix_tmpnam(char *s);
+extern char *posix_tempnam(const char *dir, const char *pfx);
+extern FILE *posix_tmpfile(void);
 
 #ifndef LIBPOSIX_INTERNAL
@@ -176 +178 @@
 
         #define tmpnam posix_tmpnam
+        #define tempnam posix_tempnam
+        #define tmpfile posix_tmpfile
 #endif
 

uspace/lib/posix/stdlib.c

@@ -40 +40 @@
 
 #include "errno.h"
+#include "fcntl.h"
 #include "limits.h"
+#include "string.h"
+#include "sys/stat.h"
+#include "unistd.h"
 
 #include "libc/sort.h"
@@ -385 +389 @@
 
 /**
- * 
- * @param tmpl
- * @return
+ * Creates and opens an unique temporary file from template.
+ *
+ * @param tmpl Template. Last six characters must be XXXXXX.
+ * @return The opened file descriptor or -1 on error.
+ */
+int posix_mkstemp(char *tmpl)
+{
+        int fd = -1;
+        
+        char *tptr = tmpl + posix_strlen(tmpl) - 6;
+        
+        while (fd < 0) {
+                if (*posix_mktemp(tmpl) == '\0') {
+                        /* Errno set by mktemp(). */
+                        return -1;
+                }
+                
+                fd = open(tmpl, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
+                
+                if (fd == -1) {
+                        /* Restore template to it's original state. */
+                        snprintf(tptr, 7, "XXXXXX");
+                }
+        }
+        
+        return fd;
+}
+
+/**
+ * Creates an unique temporary file name from template.
+ *
+ * @param tmpl Template. Last six characters must be XXXXXX.
+ * @return The value of tmpl. The template is modified in place.
+ *    If no temporary file name can be created, template is
+ *    reduced to an empty string.
  */
 char *posix_mktemp(char *tmpl)
 {
-        // TODO: low priority, just a compile-time dependency of binutils
-        not_implemented();
+        int tmpl_len = posix_strlen(tmpl);
+        if (tmpl_len < 6) {
+                errno = EINVAL;
+                *tmpl = '\0';
+                return tmpl;
+        }
+        
+        char *tptr = tmpl + tmpl_len - 6;
+        if (posix_strcmp(tptr, "XXXXXX") != 0) {
+                errno = EINVAL;
+                *tmpl = '\0';
+                return tmpl;
+        }
+        
+        static int seq = 0;
+        
+        for (; seq < 1000000; ++seq) {
+                snprintf(tptr, 7, "%06d", seq);
+                
+                int orig_errno = errno;
+                errno = 0;
+                /* Check if the file exists. */
+                if (posix_access(tmpl, F_OK) == -1) {
+                        if (errno == ENOENT) {
+                                errno = orig_errno;
+                                break;
+                        } else {
+                                /* errno set by access() */
+                                *tmpl = '\0';
+                                return tmpl;
+                        }
+                }
+        }
+        
+        if (seq == 10000000) {
+                errno = EEXIST;
+                *tmpl = '\0';
+                return tmpl;
+        }
+        
+        return tmpl;
 }
 

uspace/lib/posix/stdlib.h

@@ -113 +113 @@
 extern void posix_free(void *ptr);
 
+/* Temporary files */
+extern int posix_mkstemp(char *tmpl);
+
 /* Legacy Declarations */
 extern char *posix_mktemp(char *tmpl);
@@ -158 +161 @@
         #define free posix_free
 
+        #define mkstemp posix_mkstemp
+
         #define mktemp posix_mktemp
         #define getloadavg bsd_getloadavg