wall: remove global variables and support TMPDIR

The TMPDIR environment is preferred over _PATH_TMP in which a
file is created that is ultimately sent to terminals. This patch
will also fix compiler warnings and removes magical numbers,
which has not explanation.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/term-utils/wall.c b/term-utils/wall.c
index bc2e38288ee1b14aacbf34840c8262b0c7ad9481..d15068e969c411e4eac8f5d627e2b0b3d015e63e 100644 (file)
--- a/term-utils/wall.c
+++ b/term-utils/wall.c
@@ -66,8 +66,6 @@
 #include "carefulputc.h"
 #include "c.h"
 
-void   makemsg __P((char *));
-
 #define        IGNOREUSER      "sleeper"
 
 #ifndef MAXHOSTNAMELEN
@@ -78,9 +76,8 @@ void  makemsg __P((char *));
 # endif
 #endif
 
-int nobanner;
-int mbufsize;
-char *mbuf;
+/* Function prototypes */
+char *makemsg(char *fname, size_t *mbufsize, int print_banner);
 
 static void __attribute__((__noreturn__)) usage(void)
 {
@@ -96,16 +93,19 @@ main(int argc, char **argv) {
        struct utmp *utmpptr;
        char *p;
        char line[sizeof(utmpptr->ut_line) + 1];
+       int print_banner = TRUE;
+       char *mbuf;
+       size_t mbufsize;
 
        setlocale(LC_ALL, "");
-        bindtextdomain(PACKAGE, LOCALEDIR);
-        textdomain(PACKAGE);
+       bindtextdomain(PACKAGE, LOCALEDIR);
+       textdomain(PACKAGE);
 
        while ((ch = getopt(argc, argv, "n")) != -1) {
                switch (ch) {
                case 'n':
                        if (geteuid() == 0)
-                               nobanner = 1;
+                               print_banner = FALSE;
                        break;
                case '?':
                default:
@@ -117,9 +117,7 @@ main(int argc, char **argv) {
        if (argc > 1)
                usage();
 
-       makemsg(*argv);
-
-       setutent();
+       mbuf = makemsg(*argv, &mbufsize, print_banner);
 
        iov.iov_base = mbuf;
        iov.iov_len = mbufsize;
@@ -144,12 +142,12 @@ main(int argc, char **argv) {
                        warnx("%s", p);
        }
        endutent();
+       free(mbuf);
        exit(EXIT_SUCCESS);
 }
 
-void
-makemsg(fname)
-       char *fname;
+char *
+makemsg(char *fname, size_t *mainmbufsize, int print_banner)
 {
        register int ch, cnt;
        struct tm *lt;
@@ -158,24 +156,39 @@ makemsg(fname)
        time_t now;
        FILE *fp;
        int fd;
-       char *p, *whom, *where, hostname[MAXHOSTNAMELEN],
-               lbuf[MAXHOSTNAMELEN + 320],
-               tmpname[sizeof(_PATH_TMP) + 20];
+       char *p, *whom, *where, *hostname, *lbuf, *tmpname, *tmpenv, *mbuf;
+       size_t mbufsize;
+       long line_max;
 
-       sprintf(tmpname, "%s/wall.XXXXXX", _PATH_TMP);
-       if (!(fd = mkstemp(tmpname)) || !(fp = fdopen(fd, "r+")))
-               errx(EXIT_FAILURE, _("can't open temporary file"));
+       hostname = xmalloc(sysconf(_SC_HOST_NAME_MAX) + 1);
+       line_max = sysconf(_SC_LINE_MAX);
+       lbuf = xmalloc(line_max);
 
+       tmpname = xmalloc(PATH_MAX);
+       tmpenv = getenv("TMPDIR");
+       if ((tmpenv))
+               snprintf(tmpname, PATH_MAX, "%s/%s.XXXXXX", tmpenv,
+                       program_invocation_short_name);
+       else
+               snprintf(tmpname, PATH_MAX, "%s/%s.XXXXXX", _PATH_TMP,
+                       program_invocation_short_name);
+       if (!(fd = mkstemp(tmpname)) || !(fp = fdopen(fd, "r+")))
+               err(EXIT_FAILURE, _("can't open temporary file %s"), tmpname);
        unlink(tmpname);
+       free(tmpname);
 
-       if (!nobanner) {
+       if (print_banner == TRUE) {
                if (!(whom = getlogin()) || !*whom)
                        whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
-               if (!whom || strlen(whom) > 100)
+               if (!whom) {
                        whom = "someone";
-               where = ttyname(2);
-               if (!where || strlen(where) > 100)
+                       warn(_("cannot get passwd uid"));
+               }
+               where = ttyname(STDOUT_FILENO);
+               if (!where) {
                        where = "somewhere";
+                       warn(_("cannot get tty name"));
+               }
                gethostname(hostname, sizeof(hostname));
                time(&now);
                lt = localtime(&now);
@@ -199,6 +212,8 @@ makemsg(fname)
        }
        fprintf(fp, "%79s\r\n", " ");
 
+       free(hostname);
+
        if (fname) {
                /*
                 * When we are not root, but suid or sgid, refuse to read files
@@ -206,16 +221,16 @@ makemsg(fname)
                 * After all, our invoker can easily do "wall < file"
                 * instead of "wall file".
                 */
-               int uid = getuid();
+               uid_t uid = getuid();
                if (uid && (uid != geteuid() || getgid() != getegid()))
                        errx(EXIT_FAILURE, _("will not read %s - use stdin."),
                             fname);
 
                if (!freopen(fname, "r", stdin))
-                       errx(EXIT_FAILURE, _("can't read %s."), fname);
+                       err(EXIT_FAILURE, _("cannot open file %s"), fname);
        }
 
-       while (fgets(lbuf, sizeof(lbuf), stdin)) {
+       while (fgets(lbuf, line_max, stdin)) {
                for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) {
                        if (cnt == 79 || ch == '\n') {
                                for (; cnt < 79; ++cnt)
@@ -229,16 +244,21 @@ makemsg(fname)
                }
        }
        fprintf(fp, "%79s\r\n", " ");
+
+       free(lbuf);
        rewind(fp);
 
        if (fstat(fd, &sbuf))
                err(EXIT_FAILURE, _("fstat failed"));
 
        mbufsize = sbuf.st_size;
+       memcpy(mainmbufsize, &mbufsize, sizeof(size_t));
        mbuf = xmalloc(mbufsize);
 
        if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
                err(EXIT_FAILURE, _("fread failed"));
 
        close(fd);
+       fclose(fp);
+       return(mbuf);
 }