Add chmod

6 files changed, 380 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
index 311a8c2..e524059 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,6 +7,7 @@ config.mak
 src/include/shh-portable-utils/config.h
 basename
 cat
+chmod
 cut
 false
 true
diff --git a/package/deps.mak b/package/deps.mak
index 4703292..a90da7a 100644
--- a/package/deps.mak
+++ b/package/deps.mak
@@ -5,6 +5,7 @@
 src/shh-portable-utils/basename.o src/shh-portable-utils/basename.lo: src/shh-portable-utils/basename.c
 src/shh-portable-utils/byte_notin.o src/shh-portable-utils/byte_notin.lo: src/shh-portable-utils/byte_notin.c src/shh-portable-utils/shhfuncs.h
 src/shh-portable-utils/cat.o src/shh-portable-utils/cat.lo: src/shh-portable-utils/cat.c
+src/shh-portable-utils/chmod.o src/shh-portable-utils/chmod.lo: src/shh-portable-utils/chmod.c
 src/shh-portable-utils/cut.o src/shh-portable-utils/cut.lo: src/shh-portable-utils/cut.c src/shh-portable-utils/shhfuncs.h
 src/shh-portable-utils/false.o src/shh-portable-utils/false.lo: src/shh-portable-utils/false.c
 src/shh-portable-utils/shhgetln.o src/shh-portable-utils/shhgetln.lo: src/shh-portable-utils/shhgetln.c src/shh-portable-utils/shhfuncs.h
@@ -15,6 +16,8 @@ basename: EXTRA_LIBS := -lskarnet
 basename: src/shh-portable-utils/basename.o
 cat: EXTRA_LIBS := -lskarnet
 cat: src/shh-portable-utils/cat.o
+chmod: EXTRA_LIBS := -lskarnet
+chmod: src/shh-portable-utils/chmod.o
 cut: EXTRA_LIBS := -lskarnet
 cut: src/shh-portable-utils/cut.o src/shh-portable-utils/shhgetln.o
 false: EXTRA_LIBS :=
diff --git a/package/modes b/package/modes
index ab9464c..4c8a005 100644
--- a/package/modes
+++ b/package/modes
@@ -1,5 +1,6 @@
 basename		0755
 cat			0755
+chmod       0755
 cut			0755
 false		0755
 true		0755
diff --git a/package/targets.mak b/package/targets.mak
index 754091e..f18f34b 100644
--- a/package/targets.mak
+++ b/package/targets.mak
@@ -1,6 +1,7 @@
 BIN_TARGETS := \
 basename \
 cat \
+chmod \
 cut \
 false \
 true \
diff --git a/src/shh-portable-utils/chmod.c b/src/shh-portable-utils/chmod.c
new file mode 100644
index 0000000..cce6844
--- /dev/null
+++ b/src/shh-portable-utils/chmod.c
@@ -0,0 +1,373 @@
+#include <string.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <dirent.h>
+
+#include <skalibs/sgetopt.h>
+#include <skalibs/strerr2.h>
+#include <skalibs/types.h>
+#include <skalibs/skamisc.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/genalloc.h>
+
+#define USAGE "chmod [-R] mode file..."
+
+#define S_ISALL (S_IRWXU | S_IRWXG | S_IRWXO | S_ISUID | S_ISGID | S_ISVTX)
+
+struct chmod_directive_s {
+    mode_t who;
+    int action;
+    mode_t perm;
+    int permcopy;
+    int dir_x;
+};
+
+typedef struct chmod_directive_s chmod_directive;
+
+#define CHMOD_DIRECTIVE_ZERO { 0, 0, 0, 0, 0 }
+
+mode_t parse_octal(char const*);
+
+void parse_symbolic(char const*, genalloc*);
+
+/*
+ * Algorithm for chmod mode parsing was inspired by sbase's chmod
+ * implementation (https://core.suckless.org/sbase), so let's credit them here.
+ */
+
+int change_mode(char const*, mode_t, genalloc*, mode_t);
+
+int traverse_dir(stralloc*, mode_t, genalloc*, mode_t);
+
+int main(int argc, char const *const *argv)
+{
+    struct stat st;
+    mode_t mask;
+    mode_t mode = 0;
+    int recurse = 0;
+    int failure = 0;
+    genalloc directives = GENALLOC_ZERO;
+    subgetopt l = SUBGETOPT_ZERO;
+    PROG = "chmod";
+    for (;;) {
+        int opt = subgetopt_r(argc, argv, "R", &l);
+        if (opt == -1)
+            break;
+        switch (opt) {
+            case 'R':
+                recurse = 1;
+                break;
+            default:
+                strerr_dieusage(100, USAGE);
+        }
+    }
+    argc -= l.ind;
+    argv += l.ind;
+
+    if (argc < 2)
+        strerr_dieusage(100, USAGE);
+
+    mask = umask(0);
+    umask(mask);
+
+    if ('0' <= argv[0][0] && argv[0][0] <= '7')
+        mode = parse_octal(argv[0]);
+    else {
+        parse_symbolic(argv[0], &directives);
+        if (!genalloc_len(chmod_directive, &directives))
+            strerr_dieusage(100, USAGE);
+    }
+
+    for (char const *const *filename = argv + 1; *filename; filename++) {
+        if (stat(*filename, &st)) {
+            strerr_warnwu2sys("stat ", *filename);
+            failure = 1;
+            continue;
+        }
+        if (S_ISDIR(st.st_mode) && recurse) {
+            satmp.len = 0;
+            stralloc_catb(&satmp, *filename, strlen(*filename) + 1);
+            failure = failure || traverse_dir(&satmp, mode, &directives,
+                                              mask);
+        }
+        else
+            failure = failure || change_mode(*filename, mode, &directives,
+                                             mask);
+    }
+    return failure ? 111 : 0;
+}
+
+
+mode_t parse_octal(char const *raw_mode)
+{
+    mode_t mode = 0;
+    unsigned int m;
+    if (!uint0_oscan(raw_mode, &m))
+        strerr_dief2x(100, "invalid mode: ", raw_mode);
+
+    if (m & 0001)
+        mode |= S_IXOTH;
+    if (m & 0002)
+        mode |= S_IWOTH;
+    if (m & 0004)
+        mode |= S_IROTH;
+    if (m & 0010)
+        mode |= S_IXGRP;
+    if (m & 0020)
+        mode |= S_IWGRP;
+    if (m & 0040)
+        mode |= S_IRGRP;
+    if (m & 0100)
+        mode |= S_IXUSR;
+    if (m & 0200)
+        mode |= S_IWUSR;
+    if (m & 0400)
+        mode |= S_IRUSR;
+    if (m & 01000)
+        mode |= S_ISVTX;
+    if (m & 02000)
+        mode |= S_ISGID;
+    if (m & 04000)
+        mode |= S_ISUID;
+
+    return mode;
+}
+
+void parse_symbolic(char const *raw, genalloc *directives)
+{
+    char const *p = raw;
+    for (;;) {
+        chmod_directive d = CHMOD_DIRECTIVE_ZERO;
+        /* stage 1: parse 'who' list */
+        for (;;) {
+            if (*p == 'u')
+                d.who |= S_IRWXU | S_ISUID;
+            else if (*p == 'g')
+                d.who |= S_IRWXG | S_ISGID;
+            else if (*p == 'o')
+                d.who |= S_IRWXO;
+            else if (*p == 'a')
+                d.who |= S_IRWXU | S_IRWXG | S_IRWXO | S_ISUID | S_ISGID;
+            else
+                break;
+            p++;
+        }
+        /* stage 2: actions. First cycle is out of the loop. */
+        switch(*p) {
+            case '+':
+            case '-':
+            case '=':
+                d.action = *p;
+                break;
+            default:
+                strerr_dief2x(100, "invalid mode: ", raw);
+        }
+        p++;
+        for (;;) {
+            if (*p == 'u')
+                d.permcopy |= 1;
+            else if (*p == 'g')
+                d.permcopy |= 2;
+            else if (*p == 'o')
+                d.permcopy |= 4;
+            else if (*p == 'r')
+                d.perm |= S_IRUSR | S_IRGRP | S_IROTH;
+            else if (*p == 'w')
+                d.perm |= S_IWUSR | S_IWGRP | S_IWOTH;
+            else if (*p == 'x')
+                d.perm |= S_IXUSR | S_IXGRP | S_IXOTH;
+            else if (*p == 'X')
+                d.dir_x = 1;
+            else if (*p == 's')
+                d.perm |= S_ISUID | S_ISGID;
+            else if (*p == 't')
+                d.perm |= S_ISVTX;
+            else if (*p == ',') {
+                p++;
+                break;
+            }
+            else if (*p == '\0') {
+                if (d.perm && d.permcopy)
+                    strerr_dief2x(100, "invalid mode: ", raw);
+                if (!genalloc_append(chmod_directive, directives, &d))
+                    strerr_diefu1sys(111, "parse mode");
+                return;
+            }
+            p++;
+        }
+
+        if (d.perm && d.permcopy)
+            strerr_dief2x(100, "invalid mode: ", raw);
+        if (!genalloc_append(chmod_directive, directives, &d))
+            strerr_diefu1sys(111, "parse mode");
+
+        for (;;) {
+            d.action = d.perm = d.permcopy = d.dir_x = 0;
+            if (*p == '+' || *p == '-' || *p == '=')
+                d.action = *p;
+            else if (*p == ',')
+                break;
+            else if (*p == '\0')
+                return;
+            else
+                strerr_dief2x(100, "invalid mode: ", raw);
+
+            p++;
+
+            for (;;) {
+                if (*p == 'u')
+                    d.permcopy |= 1;
+                else if (*p == 'g')
+                    d.permcopy |= 2;
+                else if (*p == 'o')
+                    d.permcopy |= 4;
+                else if (*p == 'r')
+                    d.perm |= S_IRUSR | S_IRGRP | S_IROTH;
+                else if (*p == 'w')
+                    d.perm |= S_IWUSR | S_IWGRP | S_IWOTH;
+                else if (*p == 'x')
+                    d.perm |= S_IXUSR | S_IXGRP | S_IXOTH;
+                else if (*p == 'X')
+                    d.dir_x = 1;
+                else if (*p == 's')
+                    d.perm |= S_ISUID | S_ISGID;
+                else if (*p == 't')
+                    d.perm |= S_ISVTX;
+                else if (*p == ',') {
+                    p++;
+                    break;
+                }
+                else if (*p == '\0') {
+                    if (d.perm && d.permcopy)
+                        strerr_dief2x(100, "invalid mode: ", raw);
+                    if (!genalloc_append(chmod_directive, directives, &d))
+                        strerr_diefu1sys(111, "parse mode");
+                    return;
+                }
+                p++;
+            }
+
+            if (d.perm && d.permcopy)
+                strerr_dief2x(100, "invalid mode: ", raw);
+            if (!genalloc_append(chmod_directive, directives, &d))
+                strerr_diefu1sys(111, "parse mode");
+        }
+    }
+}
+
+int change_mode(char const *file, mode_t mode, genalloc *directives,
+                mode_t mask)
+{
+    mode_t cur_mode;
+    if (!genalloc_len(chmod_directive, directives))
+        cur_mode = mode;
+    else {
+        struct stat st;
+        mode_t who, perm, clear;
+        chmod_directive const *s = genalloc_s(chmod_directive, directives);
+        size_t len = genalloc_len(chmod_directive, directives);
+
+        if (stat(file, &st) == -1) {
+            strerr_warnwu2sys("stat ", file);
+            return 1;
+        }
+        cur_mode = st.st_mode;
+
+        for (size_t i = 0; i < len; i++) {
+            if (s[i].who) {
+                who = s[i].who;
+                clear = s[i].who;
+            }
+            else {
+                who = ~mask;
+                clear = S_ISALL;
+            }
+            perm = s[i].perm;
+
+            if (s[i].permcopy & 1) {
+                if (cur_mode & S_IRUSR)
+                    perm |= S_IRUSR | S_IRGRP | S_IROTH;
+                if (cur_mode & S_IWUSR)
+                    perm |= S_IWUSR | S_IWGRP | S_IWOTH;
+                if (cur_mode & S_IXUSR)
+                    perm |= S_IXUSR | S_IXGRP | S_IXOTH;
+            }
+            if (s[i].permcopy & 2) {
+                if (cur_mode & S_IRGRP)
+                    perm |= S_IRUSR | S_IRGRP | S_IROTH;
+                if (cur_mode & S_IWGRP)
+                    perm |= S_IWUSR | S_IWGRP | S_IWOTH;
+                if (cur_mode & S_IXGRP)
+                    perm |= S_IXUSR | S_IXGRP | S_IXOTH;
+            }
+            if (s[i].permcopy & 4) {
+                if (cur_mode & S_IROTH)
+                    perm |= S_IRUSR | S_IRGRP | S_IROTH;
+                if (cur_mode & S_IWOTH)
+                    perm |= S_IWUSR | S_IWGRP | S_IWOTH;
+                if (cur_mode & S_IXOTH)
+                    perm |= S_IXUSR | S_IXGRP | S_IXOTH;
+            }
+
+            if (s[i].dir_x && (S_ISDIR(cur_mode)
+                                || (cur_mode & (S_IXUSR | S_IXGRP | S_IXOTH))))
+                perm |= S_IXUSR | S_IXGRP | S_IXOTH;
+
+            switch (s[i].action) {
+                case '=':
+                    cur_mode &= ~clear;
+                case '+':
+                    cur_mode |= (who & perm);
+                    break;
+                case '-':
+                    cur_mode &= ~(who & perm);
+            }
+        }
+    }
+    if (chmod(file, cur_mode) == -1) {
+        strerr_warnwu2sys("change mode of ", file);
+        return 1;
+    }
+    return 0;
+}
+
+int traverse_dir(stralloc *dirname, mode_t mode, genalloc *directives,
+                 mode_t mask)
+{
+    int failure = 0;
+    size_t filename_len;
+    struct dirent *entry;
+    struct stat st;
+    DIR *dir = opendir(dirname->s);
+    if (!dir) {
+        strerr_warnwu2sys("open dir: ", dirname->s);
+        return 1;
+    }
+    while ((entry = readdir(dir))) {
+        if (!strcmp(entry->d_name, ".") || !strcmp(entry->d_name, ".."))
+            continue;
+        dirname->s[dirname->len - 1] = '/';
+        filename_len = strlen(entry->d_name);
+        if (!stralloc_catb(dirname, entry->d_name, filename_len + 1)) {
+            strerr_warnwu4sys("build file name: ", dirname->s, "/",
+                              entry->d_name);
+            failure = 1;
+            continue;
+        }
+        if (stat(dirname->s, &st) == -1) {
+            strerr_warnwu2sys("stat ", dirname->s);
+            failure = 1;
+        }
+        if (S_ISDIR(st.st_mode))
+            failure = failure || traverse_dir(dirname, mode, directives, mask);
+        else
+            failure = failure || change_mode(dirname->s, mode, directives,
+                                             mask);
+        dirname->len -= filename_len + 1;
+        dirname->s[dirname->len - 1] = '\0';
+    }
+    failure = failure || change_mode(dirname->s, mode, directives, mask);
+    closedir(dir);
+    return failure;
+}
diff --git a/src/shh-portable-utils/deps-exe/chmod b/src/shh-portable-utils/deps-exe/chmod
new file mode 100644
index 0000000..e7187fe
--- /dev/null
+++ b/src/shh-portable-utils/deps-exe/chmod
@@ -0,0 +1 @@
+-lskarnet