Merge branch 'busybox' into merge

author: Ron Yorston <rmy@pobox.com> 2021-10-13 14:37:51 +0100
committer: Ron Yorston <rmy@pobox.com> 2021-10-13 14:37:51 +0100
commit: 0ecf1aea459571b48dc68ddc2b7b9265740fa960 (patch)
tree: 491d6184a44b8b525a4ca35759d622aecd7f6344 /libbb
parent: 4859ddcb20616718efbea12c6bf8b27c469b68de (diff)
parent: aaf3d5ba74c5da97ff80b61f30cb8dd225d39096 (diff)
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8 files changed, 210 insertions, 202 deletions
diff --git a/libbb/Config.src b/libbb/Config.src
index 58c5fad50..24b31fad9 100644
--- a/libbb/Config.src
+++ b/libbb/Config.src
@@ -61,32 +61,73 @@ config SHA3_SMALL
        64-bit x86: +270 bytes of code, 45% faster
        32-bit x86: +450 bytes of code, 75% faster
-config FEATURE_FAST_TOP
+config FEATURE_NON_POSIX_CP
-        bool "Faster /proc scanning code (+100 bytes)"
+        bool "Non-POSIX, but safer, copying to special nodes"
-        default n  # all "fast or small" options default to small
+        default y
        help
-        This option makes top and ps ~20% faster (or 20% less CPU hungry),
+        With this option, "cp file symlink" will delete symlink
-        but code size is slightly bigger.
+        and create a regular file. This does not conform to POSIX,
+        but prevents a symlink attack.
+        Similarly, "cp file device" will not send file's data
+        to the device. (To do that, use "cat file >device")
-config FEATURE_ETC_NETWORKS
+config FEATURE_VERBOSE_CP_MESSAGE
-        bool "Support /etc/networks"
+        bool "Give more precise messages when copy fails (cp, mv etc)"
        default n
        help
-        Enable support for network names in /etc/networks. This is
+        Error messages with this feature enabled:
-        a rarely used feature which allows you to use names
-        instead of IP/mask pairs in route command.
-config FEATURE_ETC_SERVICES
+        $ cp file /does_not_exist/file
-        bool "Consult /etc/services even for well-known ports"
+        cp: cannot create '/does_not_exist/file': Path does not exist
-        default n
+        $ cp file /vmlinuz/file
+        cp: cannot stat '/vmlinuz/file': Path has non-directory component
+        If this feature is not enabled, they will be, respectively:
+        cp: cannot create '/does_not_exist/file': No such file or directory
+        cp: cannot stat '/vmlinuz/file': Not a directory
+        This will cost you ~60 bytes.
+config FEATURE_USE_SENDFILE
+        bool "Use sendfile system call"
+        default y
+        help
+        When enabled, busybox will use the kernel sendfile() function
+        instead of read/write loops to copy data between file descriptors
+        (for example, cp command does this a lot).
+        If sendfile() doesn't work, copying code falls back to read/write
+        loop. sendfile() was originally implemented for faster I/O
+        from files to sockets, but since Linux 2.6.33 it was extended
+        to work for many more file types.
+config FEATURE_COPYBUF_KB
+        int "Copy buffer size, in kilobytes"
+        range 1 1024
+        default 4
+        help
+        Size of buffer used by cp, mv, install, wget etc.
+        Buffers which are 4 kb or less will be allocated on stack.
+        Bigger buffers will be allocated with mmap, with fallback to 4 kb
+        stack buffer if mmap fails.
+config MONOTONIC_SYSCALL
+        bool "Use clock_gettime(CLOCK_MONOTONIC) syscall"
+        default y
+        help
+        Use clock_gettime(CLOCK_MONOTONIC) syscall for measuring
+        time intervals (time, ping, traceroute etc need this).
+        Probably requires Linux 2.6+. If not selected, gettimeofday
+        will be used instead (which gives wrong results if date/time
+        is reset).
+config IOCTL_HEX2STR_ERROR
+        bool "Use ioctl names rather than hex values in error messages"
+        default y
        help
-        Look up e.g. "telnet" and "http" in /etc/services file
+        Use ioctl names rather than hex values in error messages
-        instead of assuming ports 23 and 80.
+        (e.g. VT_DISALLOCATE rather than 0x5608). If disabled this
-        This is almost never necessary (everybody uses standard ports),
+        saves about 1400 bytes.
-        and it makes sense to avoid reading this file.
-        If you disable this option, in the cases where port is explicitly
-        specified as a service name (e.g. "telnet HOST PORTNAME"),
-        it will still be looked up in /etc/services.
 config FEATURE_EDITING
        bool "Command line editing"
@@ -302,107 +343,3 @@ config UNICODE_PRESERVE_BROKEN
        For example, this means that entering 'l', 's', ' ', 0xff, [Enter]
        at shell prompt will list file named 0xff (single char name
        with char value 255), not file named '?'.
-config FEATURE_NON_POSIX_CP
-        bool "Non-POSIX, but safer, copying to special nodes"
-        default y
-        help
-        With this option, "cp file symlink" will delete symlink
-        and create a regular file. This does not conform to POSIX,
-        but prevents a symlink attack.
-        Similarly, "cp file device" will not send file's data
-        to the device. (To do that, use "cat file >device")
-config FEATURE_VERBOSE_CP_MESSAGE
-        bool "Give more precise messages when copy fails (cp, mv etc)"
-        default n
-        help
-        Error messages with this feature enabled:
-        $ cp file /does_not_exist/file
-        cp: cannot create '/does_not_exist/file': Path does not exist
-        $ cp file /vmlinuz/file
-        cp: cannot stat '/vmlinuz/file': Path has non-directory component
-        If this feature is not enabled, they will be, respectively:
-        cp: cannot create '/does_not_exist/file': No such file or directory
-        cp: cannot stat '/vmlinuz/file': Not a directory
-        This will cost you ~60 bytes.
-config FEATURE_USE_SENDFILE
-        bool "Use sendfile system call"
-        default y
-        help
-        When enabled, busybox will use the kernel sendfile() function
-        instead of read/write loops to copy data between file descriptors
-        (for example, cp command does this a lot).
-        If sendfile() doesn't work, copying code falls back to read/write
-        loop. sendfile() was originally implemented for faster I/O
-        from files to sockets, but since Linux 2.6.33 it was extended
-        to work for many more file types.
-config FEATURE_COPYBUF_KB
-        int "Copy buffer size, in kilobytes"
-        range 1 1024
-        default 4
-        help
-        Size of buffer used by cp, mv, install, wget etc.
-        Buffers which are 4 kb or less will be allocated on stack.
-        Bigger buffers will be allocated with mmap, with fallback to 4 kb
-        stack buffer if mmap fails.
-config FEATURE_SKIP_ROOTFS
-        bool "Skip rootfs in mount table"
-        default y
-        help
-        Ignore rootfs entry in mount table.
-        In Linux, kernel has a special filesystem, rootfs, which is initially
-        mounted on /. It contains initramfs data, if kernel is configured
-        to have one. Usually, another file system is mounted over / early
-        in boot process, and therefore most tools which manipulate
-        mount table, such as df, will skip rootfs entry.
-        However, some systems do not mount anything on /.
-        If you need to configure busybox for one of these systems,
-        you may find it useful to turn this option off to make df show
-        initramfs statistics.
-        Otherwise, choose Y.
-config MONOTONIC_SYSCALL
-        bool "Use clock_gettime(CLOCK_MONOTONIC) syscall"
-        default y
-        help
-        Use clock_gettime(CLOCK_MONOTONIC) syscall for measuring
-        time intervals (time, ping, traceroute etc need this).
-        Probably requires Linux 2.6+. If not selected, gettimeofday
-        will be used instead (which gives wrong results if date/time
-        is reset).
-config IOCTL_HEX2STR_ERROR
-        bool "Use ioctl names rather than hex values in error messages"
-        default y
-        help
-        Use ioctl names rather than hex values in error messages
-        (e.g. VT_DISALLOCATE rather than 0x5608). If disabled this
-        saves about 1400 bytes.
-config FEATURE_HWIB
-        bool "Support infiniband HW"
-        default y
-        help
-        Support for printing infiniband addresses in network applets.
-config FEATURE_TIMEZONE
-        bool "Allow timezone in dates"
-        default y
-        depends on DESKTOP
-        help
-        Permit the use of timezones when parsing user-provided data
-        strings, e.g. '1996-04-09 12:45:00 -0500'.
-        This requires support for the '%z' extension to strptime() which
-        may not be available in all implementations.
diff --git a/libbb/Kbuild.src b/libbb/Kbuild.src
index 102e360af..60df3476f 100644
--- a/libbb/Kbuild.src
+++ b/libbb/Kbuild.src
@@ -21,6 +21,7 @@ lib-y += chomp.o
 lib-y += compare_string_array.o
 lib-y += concat_path_file.o
 lib-y += concat_subpath_file.o
+lib-y += const_hack.o
 lib-y += copy_file.o
 lib-y += copyfd.o
 lib-y += crc32.o
diff --git a/libbb/appletlib.c b/libbb/appletlib.c
index e1f8bf432..6c0be4a83 100644
--- a/libbb/appletlib.c
+++ b/libbb/appletlib.c
@@ -262,8 +262,7 @@ void lbb_prepare(const char *applet
                IF_FEATURE_INDIVIDUAL(, char **argv))
 {
 #ifdef bb_cached_errno_ptr
-        (*(int **)not_const_pp(&bb_errno)) = get_perrno();
+        ASSIGN_CONST_PTR(&bb_errno, get_perrno());
-        barrier();
 #endif
        applet_name = applet;
@@ -767,9 +766,9 @@ int scripted_main(int argc UNUSED_PARAM, char **argv)
        int script = find_script_by_name(applet_name);
        if (script >= 0)
 #  if ENABLE_SHELL_ASH
-                exit(ash_main(-script - 1, argv));
+                return ash_main(-script - 1, argv);
 #  elif ENABLE_SHELL_HUSH
-                exit(hush_main(-script - 1, argv));
+                return hush_main(-script - 1, argv);
 #  else
                return 1;
 #  endif
@@ -1161,10 +1160,10 @@ int scripted_main(int argc UNUSED_PARAM, char **argv)
 {
 #  if ENABLE_SHELL_ASH
        int script = 0;
-        exit(ash_main(-script - 1, argv));
+        return ash_main(-script - 1, argv);
 #  elif ENABLE_SHELL_HUSH
        int script = 0;
-        exit(hush_main(-script - 1, argv));
+        return hush_main(-script - 1, argv);
 #  else
        return 1;
 #  endif
@@ -1282,7 +1281,7 @@ int main(int argc UNUSED_PARAM, char **argv)
        full_write2_str(bb_basename(argv[0]));
        full_write2_str(": no applets enabled\n");
-        exit(127);
+        return 127;
 #else
@@ -1314,8 +1313,14 @@ int main(int argc UNUSED_PARAM, char **argv)
         || ENABLE_FEATURE_PREFER_APPLETS
         || !BB_MMU
        ) {
-                if (NUM_APPLETS > 1)
+                if (NUM_APPLETS > 1) {
-                        set_task_comm(applet_name);
+                        /* Careful, do not trash comm of "SCRIPT.sh" -
+                         * the case when started from e.g. #!/bin/ash script.
+                         * (not limited to shells - #!/bin/awk scripts also exist)
+                         */
+                        if (re_execed_comm())
+                                set_task_comm(applet_name);
+                }
        }
        parse_config_file(); /* ...maybe, if FEATURE_SUID_CONFIG */
diff --git a/libbb/const_hack.c b/libbb/const_hack.c
new file mode 100644
index 000000000..9575e6d67
--- /dev/null
+++ b/libbb/const_hack.c
@@ -0,0 +1,16 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Trick to assign a const ptr with barrier for clang
+ *
+ * Copyright (C) 2021 by YU Jincheng <shana@zju.edu.cn>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+#include "libbb.h"
+#if defined(__clang_major__) && __clang_major__ >= 9
+void FAST_FUNC XZALLOC_CONST_PTR(const void *pptr, size_t size)
+{
+        ASSIGN_CONST_PTR(pptr, xzalloc(size));
+}
+#endif
diff --git a/libbb/dump.c b/libbb/dump.c
index ffae04786..d24057325 100644
--- a/libbb/dump.c
+++ b/libbb/dump.c
@@ -568,7 +568,7 @@ static void conv_u(PR *pr, unsigned char *p)
        }
 }
-static void display(priv_dumper_t* dumper)
+static NOINLINE void display(priv_dumper_t* dumper)
 {
        unsigned char *bp;
        unsigned char savech = '\0';
diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index 7c46fa5db..8abc87976 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -135,10 +135,6 @@ enum {
                      : 0x7ff0
 };
-#if ENABLE_USERNAME_OR_HOMEDIR
-static const char null_str[] ALIGN1 = "";
-#endif
 /* We try to minimize both static and stack usage. */
 struct lineedit_statics {
        line_input_t *state;
@@ -161,12 +157,13 @@ struct lineedit_statics {
 #if ENABLE_USERNAME_OR_HOMEDIR
        char *user_buf;
-        char *home_pwd_buf; /* = (char*)null_str; */
+        char *home_pwd_buf;
+        smallint got_user_strings;
 #endif
 #if ENABLE_FEATURE_TAB_COMPLETION
-        char **matches;
        unsigned num_matches;
+        char **matches;
 #endif
 #if ENABLE_FEATURE_EDITING_WINCH
@@ -192,7 +189,7 @@ struct lineedit_statics {
 };
 /* See lineedit_ptr_hack.c */
-extern struct lineedit_statics *const lineedit_ptr_to_statics;
+extern struct lineedit_statics *BB_GLOBAL_CONST lineedit_ptr_to_statics;
 #define S (*lineedit_ptr_to_statics)
 #define state            (S.state           )
@@ -207,15 +204,15 @@ extern struct lineedit_statics *const lineedit_ptr_to_statics;
 #define prompt_last_line (S.prompt_last_line)
 #define user_buf         (S.user_buf        )
 #define home_pwd_buf     (S.home_pwd_buf    )
-#define matches          (S.matches         )
+#define got_user_strings (S.got_user_strings)
 #define num_matches      (S.num_matches     )
+#define matches          (S.matches         )
 #define delptr           (S.delptr          )
 #define newdelflag       (S.newdelflag      )
 #define delbuf           (S.delbuf          )
 #define INIT_S() do { \
-        (*(struct lineedit_statics**)not_const_pp(&lineedit_ptr_to_statics)) = xzalloc(sizeof(S)); \
+        XZALLOC_CONST_PTR(&lineedit_ptr_to_statics, sizeof(S)); \
-        barrier(); \
 } while (0)
 static void deinit_S(void)
@@ -227,14 +224,47 @@ static void deinit_S(void)
 #endif
 #if ENABLE_USERNAME_OR_HOMEDIR
        free(user_buf);
-        if (home_pwd_buf != null_str)
+        free(home_pwd_buf);
-                free(home_pwd_buf);
 #endif
        free(lineedit_ptr_to_statics);
 }
 #define DEINIT_S() deinit_S()
+#if ENABLE_USERNAME_OR_HOMEDIR
+/* Call getpwuid() only if necessary.
+ * E.g. if PS1=':', no user database reading is needed to generate prompt.
+ * (Unfortunately, default PS1='\w \$' needs it, \w abbreviates homedir
+ * as ~/... - for that it needs to *know* the homedir...)
+ */
+static void get_user_strings(void)
+{
+        struct passwd *entry;
+        got_user_strings = 1;
+        entry = getpwuid(geteuid());
+        if (entry) {
+                user_buf = xstrdup(entry->pw_name);
+                home_pwd_buf = xstrdup(entry->pw_dir);
+        }
+}
+static const char *get_username_str(void)
+{
+        if (!got_user_strings)
+                get_user_strings();
+        return user_buf ? user_buf : "";
+        /* btw, bash uses "I have no name!" string if uid has no entry */
+}
+static NOINLINE const char *get_homedir_or_NULL(void)
+{
+        if (!got_user_strings)
+                get_user_strings();
+        return home_pwd_buf;
+}
+#endif
 #if ENABLE_UNICODE_SUPPORT
 static size_t load_string(const char *src)
 {
@@ -748,11 +778,11 @@ static char *username_path_completion(char *ud)
        struct passwd *entry;
 #endif
        char *tilde_name = ud;
-        char *home = NULL;
+        const char *home = NULL;
        ud++; /* skip ~ */
        if (*ud == '/') {       /* "~/..." */
-                home = home_pwd_buf;
+                home = get_homedir_or_NULL();
 #  if !ENABLE_PLATFORM_MINGW32
        } else {
                /* "~user/..." */
@@ -1881,7 +1911,7 @@ vi_back_motion(void)
                        input_backward(1);
        }
 }
-#endif
+#endif /* ENABLE_FEATURE_EDITING_VI */
 /* Modelled after bash 4.0 behavior of Ctrl-<arrow> */
 static void ctrl_left(void)
@@ -1982,7 +2012,7 @@ static void ask_terminal(void)
        }
 }
 #else
-#define ask_terminal() ((void)0)
+# define ask_terminal() ((void)0)
 #endif
 /* Note about multi-line PS1 (e.g. "\n\w \u@\h\n> ") and prompt redrawing:
@@ -2091,7 +2121,7 @@ static void parse_and_put_prompt(const char *prmt_ptr)
                                switch (c) {
                                case 'u':
-                                        pbuf = user_buf ? user_buf : (char*)"";
+                                        pbuf = (char*)get_username_str();
                                        break;
                                case 'H':
                                case 'h':
@@ -2113,14 +2143,15 @@ static void parse_and_put_prompt(const char *prmt_ptr)
                                case 'w': /* current dir */
                                case 'W': /* basename of cur dir */
                                        if (!cwd_buf) {
+                                                const char *home;
                                                cwd_buf = xrealloc_getcwd_or_warn(NULL);
                                                if (!cwd_buf)
                                                        cwd_buf = (char *)bb_msg_unknown;
-                                                else if (home_pwd_buf[0]) {
+                                                else if ((home = get_homedir_or_NULL()) != NULL && home[0]) {
                                                        char *after_home_user;
                                                        /* /home/user[/something] -> ~[/something] */
-                                                        after_home_user = is_prefixed_with(cwd_buf, home_pwd_buf);
+                                                        after_home_user = is_prefixed_with(cwd_buf, home);
                                                        if (after_home_user
                                                         && (*after_home_user == '/' || *after_home_user == '\0')
                                                        ) {
@@ -2176,7 +2207,7 @@ static void parse_and_put_prompt(const char *prmt_ptr)
                        if (c == '\n')
                                cmdedit_prmt_len = 0;
                        else if (flg_not_length != ']') {
-#if ENABLE_UNICODE_SUPPORT
+# if ENABLE_UNICODE_SUPPORT
                                if (n == 1) {
                                        /* Only count single-byte characters and the first of multi-byte characters */
                                        if ((unsigned char)*pbuf < 0x80  /* single byte character */
@@ -2187,9 +2218,9 @@ static void parse_and_put_prompt(const char *prmt_ptr)
                                } else {
                                        cmdedit_prmt_len += unicode_strwidth(pbuf);
                                }
-#else
+# else
                                cmdedit_prmt_len += n;
-#endif
+# endif
                        }
                }
                prmt_mem_ptr = strcat(xrealloc(prmt_mem_ptr, prmt_size+1), pbuf);
@@ -2416,7 +2447,7 @@ static int32_t reverse_i_search(int timeout)
                        }
                        /* Append this char */
-#if ENABLE_UNICODE_SUPPORT
+# if ENABLE_UNICODE_SUPPORT
                        if (unicode_status == UNICODE_ON) {
                                mbstate_t mbstate = { 0 };
                                char buf[MB_CUR_MAX + 1];
@@ -2427,7 +2458,7 @@ static int32_t reverse_i_search(int timeout)
                                                strcpy(match_buf + match_buf_len, buf);
                                }
                        } else
-#endif
+# endif
                        if (match_buf_len < sizeof(match_buf) - 1) {
                                match_buf[match_buf_len] = ic;
                                match_buf[match_buf_len + 1] = '\0';
@@ -2479,7 +2510,7 @@ static int32_t reverse_i_search(int timeout)
        return ic;
 }
-#endif
+#endif /* ENABLE_FEATURE_REVERSE_SEARCH */
 #if ENABLE_FEATURE_EDITING_WINCH
 static void sigaction2(int sig, struct sigaction *act)
@@ -2521,7 +2552,6 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
        //command_len = 0; - done by INIT_S()
        //cmdedit_y = 0;  /* quasireal y, not true if line > xt*yt */
        cmdedit_termw = 80;
-        IF_USERNAME_OR_HOMEDIR(home_pwd_buf = (char*)null_str;)
        IF_FEATURE_EDITING_VI(delptr = delbuf;)
 #if !ENABLE_PLATFORM_MINGW32
@@ -2589,18 +2619,6 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
        tcsetattr_stdin_TCSANOW(&new_settings);
 #endif
-#if ENABLE_USERNAME_OR_HOMEDIR
-        {
-                struct passwd *entry;
-                entry = getpwuid(geteuid());
-                if (entry) {
-                        user_buf = xstrdup(entry->pw_name);
-                        home_pwd_buf = xstrdup(entry->pw_dir);
-                }
-        }
-#endif
 #if 0
        for (i = 0; i <= state->max_history; i++)
                bb_error_msg("history[%d]:'%s'", i, state->history[i]);
diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c
index 885c19f1a..151739ae2 100644
--- a/libbb/vfork_daemon_rexec.c
+++ b/libbb/vfork_daemon_rexec.c
@@ -28,6 +28,22 @@
 # ifndef PR_GET_NAME
 # define PR_GET_NAME 16
 # endif
+# if ENABLE_FEATURE_SH_STANDALONE || ENABLE_FEATURE_PREFER_APPLETS || !BB_MMU
+int FAST_FUNC re_execed_comm(void)
+{
+        const char *e, *expected_comm;
+        char comm[16];
+        BUILD_BUG_ON(CONFIG_BUSYBOX_EXEC_PATH[0] != '/');
+        e = CONFIG_BUSYBOX_EXEC_PATH;
+        /* Hopefully (strrchr(e) - e) evaluates to constant at compile time: */
+        expected_comm = bb_busybox_exec_path + (strrchr(e, '/') - e) + 1;
+        prctl(PR_GET_NAME, (long)comm, 0, 0, 0);
+        //bb_error_msg("comm:'%.*s' expected:'%s'", 16, comm, expected_comm);
+        return strcmp(comm, expected_comm) == 0;
+}
+# endif
 void FAST_FUNC set_task_comm(const char *comm)
 {
        /* okay if too long (truncates) */
diff --git a/libbb/xreadlink.c b/libbb/xreadlink.c
index 31680810b..024ee9047 100644
--- a/libbb/xreadlink.c
+++ b/libbb/xreadlink.c
@@ -130,7 +130,7 @@ char* FAST_FUNC xmalloc_realpath(const char *path)
 #endif
 }
-char* FAST_FUNC xmalloc_realpath_coreutils(const char *path)
+char* FAST_FUNC xmalloc_realpath_coreutils(char *path)
 {
        char *buf;
@@ -144,32 +144,19 @@ char* FAST_FUNC xmalloc_realpath_coreutils(const char *path)
         * (the directory must exist).
         */
        if (!buf && errno == ENOENT) {
-                char *last_slash = strrchr(path, '/');
+                char *target, c, *last_slash;
-                if (last_slash) {
+                size_t i;
-                        *last_slash++ = '\0';
-                        buf = xmalloc_realpath(path);
+                target = xmalloc_readlink(path);
-                        if (buf) {
+                if (target) {
-                                unsigned len = strlen(buf);
+                        /*
-                                buf = xrealloc(buf, len + strlen(last_slash) + 2);
+                         * $ ln -s /bin/qwe symlink  # note: /bin is a link to /usr/bin
-                                buf[len++] = '/';
+                         * $ readlink -f symlink
-                                strcpy(buf + len, last_slash);
+                         * /usr/bin/qwe
-                        }
+                         * $ realpath symlink
-                } else {
+                         * /usr/bin/qwe
-                        char *target = xmalloc_readlink(path);
+                         */
-                        if (target) {
+                        if (target[0] != '/') {
-                                char *cwd;
-                                if (target[0] == '/') {
-                                        /*
-                                         * $ ln -s /bin/qwe symlink  # note: /bin is a link to /usr/bin
-                                         * $ readlink -f symlink
-                                         * /usr/bin/qwe/target_does_not_exist
-                                         * $ realpath symlink
-                                         * /usr/bin/qwe/target_does_not_exist
-                                         */
-                                        buf = xmalloc_realpath_coreutils(target);
-                                        free(target);
-                                        return buf;
-                                }
                                /*
                                 * $ ln -s target_does_not_exist symlink
                                 * $ readlink -f symlink
@@ -177,13 +164,41 @@ char* FAST_FUNC xmalloc_realpath_coreutils(const char *path)
                                 * $ realpath symlink
                                 * /CURDIR/target_does_not_exist
                                 */
-                                cwd = xrealloc_getcwd_or_warn(NULL);
+                                char *cwd = xrealloc_getcwd_or_warn(NULL);
-                                buf = concat_path_file(cwd, target);
+                                char *tmp = concat_path_file(cwd, target);
                                free(cwd);
                                free(target);
-                                return buf;
+                                target = tmp;
+                        }
+                        buf = xmalloc_realpath_coreutils(target);
+                        free(target);
+                        return buf;
+                }
+                /* ignore leading and trailing slashes */
+                while (path[0] == '/' && path[1] == '/')
+                        ++path;
+                i = strlen(path) - 1;
+                while (i > 0 && path[i] == '/')
+                        i--;
+                c = path[i + 1];
+                path[i + 1] = '\0';
+                last_slash = strrchr(path, '/');
+                if (last_slash == path)
+                        buf = xstrdup(path);
+                else if (last_slash) {
+                        *last_slash = '\0';
+                        buf = xmalloc_realpath(path);
+                        *last_slash++ = '/';
+                        if (buf) {
+                                unsigned len = strlen(buf);
+                                buf = xrealloc(buf, len + strlen(last_slash) + 2);
+                                buf[len++] = '/';
+                                strcpy(buf + len, last_slash);
                        }
                }
+                path[i + 1] = c;
        }
        return buf;
author	Ron Yorston <rmy@pobox.com>	2021-10-13 14:37:51 +0100
committer	Ron Yorston <rmy@pobox.com>	2021-10-13 14:37:51 +0100
commit	0ecf1aea459571b48dc68ddc2b7b9265740fa960 (patch)
tree	491d6184a44b8b525a4ca35759d622aecd7f6344 /libbb
parent	4859ddcb20616718efbea12c6bf8b27c469b68de (diff)
parent	aaf3d5ba74c5da97ff80b61f30cb8dd225d39096 (diff)
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