X-Git-Url: https://diplodocus.org/git/nmh/blobdiff_plain/a30e7865b46712fe346d8a91894ab68aac664901..2417770134dfb5e942934143c41b4545400f0018:/sbr/utils.c

diff --git a/sbr/utils.c b/sbr/utils.c
index f103167c..c9769fb0 100644
--- a/sbr/utils.c
+++ b/sbr/utils.c
@@ -25,62 +25,75 @@ extern char *mhdocdir;
  */
 #define MAXMSGS 256
 
-/*
- * Safely call malloc
- */
-void *
-mh_xmalloc(size_t size)
+/* Call malloc(3), exiting on NULL return. */
+void *mh_xmalloc(size_t size)
 {
-    void *memory;
+    void *p;
 
     if (size == 0)
-        adios(NULL, "Tried to malloc 0 bytes");
-
-    memory = malloc(size);
-    if (!memory)
-        adios(NULL, "Malloc failed");
+        size = 1; /* Some mallocs don't like 0. */
+    p = malloc(size);
+    if (!p)
+        adios(NULL, "malloc failed, size wanted: %zu", size);
 
-    return memory;
+    return p;
 }
 
-/*
- * Safely call realloc
- */
-void *
-mh_xrealloc(void *ptr, size_t size)
+/* Call realloc(3), exiting on NULL return. */
+void *mh_xrealloc(void *ptr, size_t size)
 {
-    void *memory;
+    void *new;
 
-    /* Some non-POSIX realloc()s don't cope with realloc(NULL,sz) */
+    /* Copy POSIX behaviour, coping with non-POSIX systems. */
+    if (size == 0) {
+        if (ptr) {
+            free(ptr);
+        }
+        return mh_xmalloc(1); /* Get a unique pointer. */
+    }
     if (!ptr)
         return mh_xmalloc(size);
 
-    if (size == 0)
-        adios(NULL, "Tried to realloc 0bytes");
+    new = realloc(ptr, size);
+    if (!new)
+        adios(NULL, "realloc failed, size wanted: %zu", size);
+
+    return new;
+}
 
-    memory = realloc(ptr, size);
-    if (!memory)
-        adios(NULL, "Realloc failed");
+/* Call calloc(3), exiting on NULL return. */
+void *mh_xcalloc(size_t nelem, size_t elsize)
+{
+    void *p;
+
+    if (!nelem || !elsize)
+        return mh_xmalloc(1); /* Get a unique pointer. */
+
+    p = calloc(nelem, elsize);
+    if (!p)
+        adios(NULL, "calloc failed, size wanted: %zu * %zu", nelem, elsize);
 
-    return memory;
+    return p;
 }
 
-/*
- * Safely call calloc
- */
-void *
-mh_xcalloc(size_t nmemb, size_t size)
+/* Duplicate a NUL-terminated string, exit on failure. */
+char *mh_xstrdup(const char *src)
 {
-    void *memory;
+    size_t n;
+    char *dest;
 
-    if (nmemb == 0  ||  size == 0)
-        adios(NULL, "Tried to calloc 0 bytes");
+    n = strlen(src) + 1; /* Ignore possibility of overflow. */
+    dest = mh_xmalloc(n);
+    memcpy(dest, src, n);
 
-    if ((memory = calloc(nmemb, size))) {
-        return memory;
-    } else {
-        adios(NULL, "calloc failed");
-    }
+    return dest;
+}
+
+/* Call free(3), if ptr isn't NULL. */
+void mh_xfree(void *ptr)
+{
+    if (ptr)
+        free(ptr); /* Some very old platforms can't cope with NULL. */
 }
 
 /*
@@ -90,7 +103,7 @@ mh_xcalloc(size_t nmemb, size_t size)
 char *
 pwd(void)
 {
-    register char *cp;
+    char *cp;
     static char curwd[PATH_MAX];
 
     if (!getcwd (curwd, PATH_MAX)) {
@@ -367,24 +380,38 @@ nmh_init(const char *argv0, int read_context) {
 
     /* Read context, if supposed to. */
     if (read_context) {
+        int allow_version_check = 1;
+        int check_older_version = 0;
+        char *cp;
+
         context_read();
 
-        /* Check to see if the user is running a different version of nmh
-           than they had last run, and notify them if so.  But only if
-           read_context was set to a value to enable this. */
-        if (read_context == 1  &&  isatty (fileno (stdin))  &&
+        if (read_context != 1  ||
+            ((cp = context_find ("Welcome")) && strcasecmp (cp, "disable") == 0)) {
+            allow_version_check = 0;
+        } else if ((cp = getenv ("MHCONTEXT")) != NULL && *cp != '\0') {
+            /* Context file comes from $MHCONTEXT, so only print the message
+               if the context file has an older version.  If it does, or if it
+               doesn't have a version at all, update the version. */
+            check_older_version = 1;
+        }
+
+        /* Check to see if the user is running a different (or older, if
+           specified) version of nmh than they had run bfore, and notify them
+           if so.  But only if read_context was set to a value to enable. */
+        if (allow_version_check  &&  isatty (fileno (stdin))  &&
             isatty (fileno (stdout))  &&  isatty (fileno (stderr))) {
-            if (nmh_version_changed ()) {
+            if (nmh_version_changed (check_older_version)) {
                 printf ("==================================================="
-                        "====================\n");
+                        "=====================\n");
                 printf ("Welcome to nmh version %s\n\n", VERSION);
-                printf ("See the release notes in %s/NEWS .\n\n",
+                printf ("See the release notes in %s/NEWS\n\n",
                          mhdocdir);
                 print_intro (stdout, 1);
                 printf ("\nThis message will not be repeated until "
                         "nmh is next updated.\n");
                 printf ("==================================================="
-                        "====================\n\n");
+                        "=====================\n\n");
 
                 fputs ("Press enter to continue: ", stdout);
                 (void) read_line ();
@@ -396,7 +423,7 @@ nmh_init(const char *argv0, int read_context) {
     } else {
         int status = context_foil(NULL);
         if (status != OK) {
-            advise("", "failed to create minimal profile/conext");
+            advise("", "failed to create minimal profile/context");
         }
         return status;
     }
@@ -404,20 +431,36 @@ nmh_init(const char *argv0, int read_context) {
 
 
 /*
- * Check stored version, and if out-of-date or non-existent, notify the user
- * and update.
+ * Check stored version, and return 1 if out-of-date or non-existent.
+ * Because the output of "mhparam version" is prefixed with "nmh-",
+ * use that prefix here.
  */
 int
-nmh_version_changed () {
-    const char *const old_version = context_find("Version");
-
-    /* mhparam version includes the nmh- prefix, so be consistent with that. */
-    if (old_version == NULL  ||  strcmp(old_version, "nmh-" VERSION) != 0) {
-        context_replace ("Version", "nmh-" VERSION);
+nmh_version_changed (int older) {
+    const char *const context_version = context_find("Version");
+
+    if (older) {
+        /* Convert the version strings to floats and compare them.  This will
+           break for versions with multiple decimal points, etc. */
+        const float current_version = strtof (VERSION, NULL);
+        const float old_version =
+            context_version  &&  strncmp (context_version, "nmh-", 4) == 0
+            ?  strtof (context_version + 4, NULL)
+            :  99999999;
+
+        if (context_version == NULL  ||  old_version < current_version) {
+            context_replace ("Version", "nmh-" VERSION);
+        }
 
-        return 1;
+        return old_version < current_version  ?  1  :  0;
     } else {
-        return 0;
+        if (context_version == NULL  ||  strcmp(context_version, "nmh-" VERSION) != 0) {
+            context_replace ("Version", "nmh-" VERSION);
+
+            return 1;
+        } else {
+            return 0;
+        }
     }
 }
 
@@ -454,3 +497,25 @@ contains8bit(const char *start, const char *end)
 
     return 0;
 }
+
+
+/*
+ * See if input has any 8-bit bytes.
+ */
+int
+scan_input (int fd, int *eightbit) {
+    int state;
+    char buf[BUFSIZ];
+
+    *eightbit = 0;
+    lseek (fd, (off_t) 0, SEEK_SET);
+
+    while ((state = read (fd, buf, sizeof buf)) > 0) {
+        if (contains8bit (buf, buf + state)) {
+            *eightbit = 1;
+            return OK;
+        }
+    }
+
+    return state == NOTOK  ?  NOTOK  :  OK;
+}