1 files changed, 92 insertions, 0 deletions
diff --git a/documentation/libelf-by-example/prog4.txt b/documentation/libelf-by-example/prog4.txt
new file mode 100644
index 0000000000000..465f9df595d7b
--- /dev/null
+++ b/documentation/libelf-by-example/prog4.txt
@@ -0,0 +1,92 @@
+/*
+ * Print the names of ELF sections.
+ *
+ * $Id: prog4.txt 2133 2011-11-10 08:28:22Z jkoshy $
+ */
+
+#include <err.h>
+#include <fcntl.h>
+#include <gelf.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <vis.h>
+
+int
+main(int argc, char **argv)
+{
+    int fd;
+    Elf *e;
+    char *name, *p, pc[4*sizeof(char)];
+    Elf_Scn *scn;
+    Elf_Data *data;
+    GElf_Shdr shdr;
+    size_t n, shstrndx, sz;
+
+    if (argc != 2)
+        errx(EXIT_FAILURE, "usage: %s file-name", argv[0]);
+
+    if (elf_version(EV_CURRENT) == EV_NONE)
+        errx(EXIT_FAILURE, "ELF library initialization "
+            "failed: %s", elf_errmsg(-1));
+
+    if ((fd = open(argv[1], O_RDONLY, 0)) < 0)
+        err(EXIT_FAILURE, "open \%s\" failed", argv[1]);
+
+    if ((e = elf_begin(fd, ELF_C_READ, NULL)) == NULL)
+        errx(EXIT_FAILURE, "elf_begin() failed: %s.",
+            elf_errmsg(-1));
+
+    if (elf_kind(e) != ELF_K_ELF)
+        errx(EXIT_FAILURE, "%s is not an ELF object.",
+            argv[1]);
+
+    if (elf_getshdrstrndx(e, &shstrndx) != 0) @\co{1}@
+        errx(EXIT_FAILURE, "elf_getshdrstrndx() failed: %s.",
+            elf_errmsg(-1));
+
+    scn = NULL; @\co{2}@
+    while ((scn = elf_nextscn(e, scn)) != NULL) { @\co{3}@
+        if (gelf_getshdr(scn, &shdr) != &shdr) @\co{4}@
+            errx(EXIT_FAILURE, "getshdr() failed: %s.",
+                elf_errmsg(-1));
+
+        if ((name = elf_strptr(e, shstrndx, shdr.sh_name))
+            == NULL) @\co{5}@
+            errx(EXIT_FAILURE, "elf_strptr() failed: %s.",
+                elf_errmsg(-1));
+
+        (void) printf("Section %-4.4jd %s\n", (uintmax_t)
+            elf_ndxscn(scn), name);
+    }
+
+    if ((scn = elf_getscn(e, shstrndx)) == NULL) @\co{6}@
+        errx(EXIT_FAILURE, "getscn() failed: %s.",
+            elf_errmsg(-1));
+
+    if (gelf_getshdr(scn, &shdr) != &shdr)
+        errx(EXIT_FAILURE, "getshdr(shstrndx) failed: %s.",
+            elf_errmsg(-1));
+
+    (void) printf(".shstrab: size=%jd\n", (uintmax_t)
+        shdr.sh_size);
+
+    data = NULL; n = 0;
+    while (n < shdr.sh_size &&
+           (data = elf_getdata(scn, data)) != NULL) { @\co{7}@
+        p = (char *) data->d_buf;
+        while (p < (char *) data->d_buf + data->d_size) {
+            if (vis(pc, *p, VIS_WHITE, 0))
+                printf("%s", pc);
+            n++; p++;
+            (void) putchar((n % 16) ? ' ' : '\n');
+        }
+    }
+    (void) putchar('\n');
+
+    (void) elf_end(e);
+    (void) close(fd);
+    exit(EXIT_SUCCESS);
+}
+