Changeset 3621 in MondoRescue for branches/3.3/mindi-busybox/coreutils/head.c

Timestamp:

Dec 20, 2016, 4:07:32 PM (7 years ago)

Author:

Bruno Cornec

Message:

New 3?3 banch for incorporation of latest busybox 1.25. Changing minor version to handle potential incompatibilities.

Location:

branches/3.3

Files:

• . (copied) (copied from branches/3.2 )
• mindi-busybox/coreutils/head.c (modified) (10 diffs)

branches/3.3/mindi-busybox/coreutils/head.c

@@ -12 +12 @@
 /* http://www.opengroup.org/onlinepubs/007904975/utilities/head.html */
 
+//kbuild:lib-$(CONFIG_HEAD) += head.o
+
 //usage:#define head_trivial_usage
 //usage:       "[OPTIONS] [FILE]..."
@@ -19 +21 @@
 //usage:     "\n    -n N[kbm]   Print first N lines"
 //usage:    IF_FEATURE_FANCY_HEAD(
-//usage:     "\n    -c N[kbm]   Print first N bytes"
+//usage:     "\n    -n -N[kbm]  Print all except N last lines"
+//usage:     "\n    -c [-]N[kbm]    Print first N bytes"
 //usage:     "\n    -q      Never print headers"
 //usage:     "\n    -v      Always print headers"
@@ -35 +38 @@
 /* This is a NOEXEC applet. Be very careful! */
 
+#if !ENABLE_FEATURE_FANCY_HEAD
+# define print_first_N(fp,count,bytes) print_first_N(fp,count)
+#endif
+static void
+print_first_N(FILE *fp, unsigned long count, bool count_bytes)
+{
+#if !ENABLE_FEATURE_FANCY_HEAD
+    const int count_bytes = 0;
+#endif
+    while (count) {
+        int c = getc(fp);
+        if (c == EOF)
+            break;
+        if (count_bytes || (c == '\n'))
+            --count;
+        putchar(c);
+    }
+}
+
+#if ENABLE_FEATURE_FANCY_HEAD
+static void
+print_except_N_last_bytes(FILE *fp, unsigned count)
+{
+    unsigned char *circle = xmalloc(++count);
+    unsigned head = 0;
+    for(;;) {
+        int c;
+        c = getc(fp);
+        if (c == EOF)
+            goto ret;
+        circle[head++] = c;
+        if (head == count)
+            break;
+    }
+    for (;;) {
+        int c;
+        if (head == count)
+            head = 0;
+        putchar(circle[head]);
+        c = getc(fp);
+        if (c == EOF)
+            goto ret;
+        circle[head] = c;
+        head++;
+    }
+ ret:
+    free(circle);
+}
+
+static void
+print_except_N_last_lines(FILE *fp, unsigned count)
+{
+    char **circle = xzalloc((++count) * sizeof(circle[0]));
+    unsigned head = 0;
+    for(;;) {
+        char *c;
+        c = xmalloc_fgets(fp);
+        if (!c)
+            goto ret;
+        circle[head++] = c;
+        if (head == count)
+            break;
+    }
+    for (;;) {
+        char *c;
+        if (head == count)
+            head = 0;
+        fputs(circle[head], stdout);
+        c = xmalloc_fgets(fp);
+        if (!c)
+            goto ret;
+        free(circle[head]);
+        circle[head++] = c;
+    }
+ ret:
+    head = 0;
+    for(;;) {
+        free(circle[head++]);
+        if (head == count)
+            break;
+    }
+    free(circle);
+}
+#else
+/* Must never be called */
+void print_except_N_last_bytes(FILE *fp, unsigned count);
+void print_except_N_last_lines(FILE *fp, unsigned count);
+#endif
+
+#if !ENABLE_FEATURE_FANCY_HEAD
+# define eat_num(negative_N,p) eat_num(p)
+#endif
+static unsigned long
+eat_num(bool *negative_N, const char *p)
+{
+#if ENABLE_FEATURE_FANCY_HEAD
+    if (*p == '-') {
+        *negative_N = 1;
+        p++;
+    }
+#endif
+    return xatoul_sfx(p, bkm_suffixes);
+}
+
 static const char head_opts[] ALIGN1 =
     "n:"
@@ -42 +149 @@
     ;
 
-static const struct suffix_mult head_suffixes[] = {
-    { "b", 512 },
-    { "k", 1024 },
-    { "m", 1024*1024 },
-    { "", 0 }
-};
-
 #define header_fmt_str "\n==> %s <==\n"
 
@@ -55 +155 @@
 {
     unsigned long count = 10;
-    unsigned long i;
-#if ENABLE_FEATURE_FANCY_HEAD
-    int count_bytes = 0;
+#if ENABLE_FEATURE_FANCY_HEAD
     int header_threshhold = 1;
+    bool count_bytes = 0;
+    bool negative_N = 0;
+#else
+# define header_threshhold 1
+# define count_bytes       0
+# define negative_N        0
 #endif
     FILE *fp;
@@ -64 +168 @@
     char *p;
     int opt;
-    int c;
     int retval = EXIT_SUCCESS;
 
@@ -74 +177 @@
         --argc;
         ++argv;
-        p = (*argv) + 1;
+        p = argv[0] + 1;
         goto GET_COUNT;
     }
@@ -98 +201 @@
  GET_COUNT:
 #endif
-            count = xatoul_sfx(p, head_suffixes);
+            count = eat_num(&negative_N, p);
             break;
         default:
@@ -111 +214 @@
 
     fmt = header_fmt_str + 1;
-#if ENABLE_FEATURE_FANCY_HEAD
     if (argc <= header_threshhold) {
+#if ENABLE_FEATURE_FANCY_HEAD
         header_threshhold = 0;
-    }
 #else
-    if (argc <= 1) {
         fmt += 11; /* "" */
-    }
-    /* Now define some things here to avoid #ifdefs in the code below.
-     * These should optimize out of the if conditions below. */
-#define header_threshhold   1
-#define count_bytes         0
-#endif
+#endif
+    }
+    if (negative_N) {
+        if (count >= INT_MAX / sizeof(char*))
+            bb_error_msg("count is too big: %lu", count);
+    }
 
     do {
@@ -134 +235 @@
                 printf(fmt, *argv);
             }
-            i = count;
-            while (i && ((c = getc(fp)) != EOF)) {
-                if (count_bytes || (c == '\n')) {
-                    --i;
+            if (negative_N) {
+                if (count_bytes) {
+                    print_except_N_last_bytes(fp, count);
+                } else {
+                    print_except_N_last_lines(fp, count);
                 }
-                putchar(c);
-            }
+            } else {
+                print_first_N(fp, count, count_bytes);
+            }
+            die_if_ferror_stdout();
             if (fclose_if_not_stdin(fp)) {
                 bb_simple_perror_msg(*argv);
                 retval = EXIT_FAILURE;
             }
-            die_if_ferror_stdout();
         } else {
             retval = EXIT_FAILURE;