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authorAshwini Sharma <devnull@localhost>2014-10-30 18:36:09 -0500
committerAshwini Sharma <devnull@localhost>2014-10-30 18:36:09 -0500
commit7a976a09cc2327dcf0baf8708d3420136dfbc3fc (patch)
tree4e4def8c7faeb0b6c55dce4f11afdd34f52b6ea4 /toys/pending/crontab.c
parent82671e1ed5f06e016398f3d2de5f3c2ba388713d (diff)
downloadtoybox-7a976a09cc2327dcf0baf8708d3420136dfbc3fc.tar.gz
Attached are new toys TR and CRONTAB.
*tr.c*: It translate, squezze and delete characters. Supported classes are alpha, alnum, digit, lower, upper space, blank, puct, cntrl and xdigit. *crontab.c*: Companion of crond. It maintains crontab files.
Diffstat (limited to 'toys/pending/crontab.c')
-rw-r--r--toys/pending/crontab.c366
1 files changed, 366 insertions, 0 deletions
diff --git a/toys/pending/crontab.c b/toys/pending/crontab.c
new file mode 100644
index 00000000..35f6d659
--- /dev/null
+++ b/toys/pending/crontab.c
@@ -0,0 +1,366 @@
+/* crontab.c - files used to schedule the execution of programs.
+ *
+ * Copyright 2014 Ranjan Kumar <ranjankumar.bth@gmail.com>
+ *
+ * http://pubs.opengroup.org/onlinepubs/9699919799/utilities/crontab.html
+
+USE_CRONTAB(NEWTOY(crontab, "c:u:elr[!elr]", TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_STAYROOT))
+
+config CRONTAB
+ bool "crontab"
+ default n
+ help
+ usage: crontab [-u user] FILE
+ [-u user] [-e | -l | -r]
+ [-c dir]
+
+ Files used to schedule the execution of programs.
+
+ -c crontab dir
+ -e edit user's crontab
+ -l list user's crontab
+ -r delete user's crontab
+ -u user
+ FILE Replace crontab by FILE ('-': stdin)
+*/
+#define FOR_crontab
+#include "toys.h"
+
+GLOBALS(
+ char *user;
+ char *cdir;
+)
+
+static char *omitspace(char *line)
+{
+ while (*line == ' ' || *line == '\t') line++;
+ return line;
+}
+
+/*
+ * Names can also be used for the 'month' and 'day of week' fields
+ * (First three letters of the particular day or month).
+ */
+static int getindex(char *src, int size)
+{
+ int i;
+ char days[]={"sun""mon""tue""wed""thu""fri""sat"};
+ char months[]={"jan""feb""mar""apr""may""jun""jul"
+ "aug""sep""oct""nov""dec"};
+ char *field = (size == 12) ? months : days;
+
+ // strings are not allowed for min, hour and dom fields.
+ if (!(size == 7 || size == 12)) return -1;
+
+ for (i = 0; field[i]; i += 3) {
+ if (!strncasecmp(src, &field[i], 3))
+ return (i/3);
+ }
+ return -1;
+}
+
+static long getval(char *num, long low, long high)
+{
+ long val = strtol(num, &num, 10);
+
+ if (*num || (val < low) || (val > high)) return -1;
+ return val;
+}
+
+// Validate minute, hour, day of month, month and day of week fields.
+static int validate_component(int min, int max, char *src)
+{
+ int skip = 0;
+ char *ptr;
+
+ if (!src) return 1;
+ if ((ptr = strchr(src, '/'))) {
+ *ptr++ = 0;
+ if ((skip = getval(ptr, min, (min ? max: max-1))) < 0) return 1;
+ }
+
+ if (*src == '-' || *src == ',') return 1;
+ if (*src == '*') {
+ if (*(src+1)) return 1;
+ }
+ else {
+ for (;;) {
+ char *ctoken = strsep(&src, ","), *dtoken;
+
+ if (!ctoken) break;
+ if (!*ctoken) return 1;
+
+ // validate start position.
+ dtoken = strsep(&ctoken, "-");
+ if (isdigit(*dtoken)) {
+ if (getval(dtoken, min, (min ? max : max-1)) < 0) return 1;
+ } else if (getindex(dtoken, max) < 0) return 1;
+
+ // validate end position.
+ if (!ctoken) {
+ if (skip) return 1; // case 10/20 or 1,2,4/3
+ }
+ else if (*ctoken) {// e.g. N-M
+ if (isdigit(*ctoken)) {
+ if (getval(ctoken, min, (min ? max : max-1)) < 0) return 1;
+ } else if (getindex(ctoken, max) < 0) return 1;
+ } else return 1; // error condition 'N-'
+ }
+ }
+ return 0;
+}
+
+static int parse_crontab(char *fname)
+{
+ char *line;
+ int lno, fd = xopen(fname, O_RDONLY);
+ long plen = 0;
+
+ for (lno = 1; (line = get_rawline(fd, &plen, '\n')); lno++,free(line)) {
+ char *name, *val, *tokens[5] = {0,}, *ptr = line;
+ int count = 0;
+
+ if (line[plen - 1] == '\n') line[--plen] = '\0';
+ else {
+ snprintf(toybuf, sizeof(toybuf), "'%d': premature EOF\n", lno);
+ goto OUT;
+ }
+
+ ptr = omitspace(ptr);
+ if (!*ptr || *ptr == '#' || *ptr == '@') continue;
+ while (count<5) {
+ int len = strcspn(ptr, " \t");
+
+ if (ptr[len]) ptr[len++] = '\0';
+ tokens[count++] = ptr;
+ ptr += len;
+ ptr = omitspace(ptr);
+ if (!*ptr) break;
+ }
+ switch (count) {
+ case 1: // form SHELL=/bin/sh
+ name = tokens[0];
+ if ((val = strchr(name, '='))) *val++ = 0;
+ if (!val || !*val) {
+ snprintf(toybuf, sizeof(toybuf), "'%d': %s\n", lno, line);
+ goto OUT;
+ }
+ break;
+ case 2: // form SHELL =/bin/sh or SHELL= /bin/sh
+ name = tokens[0];
+ if ((val = strchr(name, '='))) {
+ *val = 0;
+ val = tokens[1];
+ } else {
+ if (*(tokens[1]) != '=') {
+ snprintf(toybuf, sizeof(toybuf), "'%d': %s\n", lno, line);
+ goto OUT;
+ }
+ val = tokens[1] + 1;
+ }
+ if (!*val) {
+ snprintf(toybuf, sizeof(toybuf), "'%d': %s\n", lno, line);
+ goto OUT;
+ }
+ break;
+ case 3: // NAME = VAL
+ name = tokens[0];
+ val = tokens[2];
+ if (*(tokens[1]) != '=') {
+ snprintf(toybuf, sizeof(toybuf), "'%d': %s\n", lno, line);
+ goto OUT;
+ }
+ break;
+ default:
+ if (validate_component(0, 60, tokens[0])) {
+ snprintf(toybuf, sizeof(toybuf), "'%d': bad minute\n", lno);
+ goto OUT;
+ }
+ if (validate_component(0, 24, tokens[1])) {
+ snprintf(toybuf, sizeof(toybuf), "'%d': bad hour\n", lno);
+ goto OUT;
+ }
+ if (validate_component(1, 31, tokens[2])) {
+ snprintf(toybuf, sizeof(toybuf), "'%d': bad day-of-month\n", lno);
+ goto OUT;
+ }
+ if (validate_component(1, 12, tokens[3])) {
+ snprintf(toybuf, sizeof(toybuf), "'%d': bad month\n", lno);
+ goto OUT;
+ }
+ if (validate_component(0, 7, tokens[4])) {
+ snprintf(toybuf, sizeof(toybuf), "'%d': bad day-of-week\n", lno);
+ goto OUT;
+ }
+ if (!*ptr) { // don't have any cmd to execute.
+ snprintf(toybuf, sizeof(toybuf), "'%d': bad command\n", lno);
+ goto OUT;
+ }
+ break;
+ }
+ }
+ xclose(fd);
+ return 0;
+OUT:
+ free(line);
+ printf("Error at line no %s", toybuf);
+ xclose(fd);
+ return 1;
+}
+
+static void do_list(char *name)
+{
+ int fdin;
+
+ snprintf(toybuf, sizeof(toybuf), "%s%s", TT.cdir, name);
+ if ((fdin = open(toybuf, O_RDONLY)) == -1)
+ error_exit("No crontab for '%s'", name);
+ xsendfile(fdin, 1);
+ xclose(fdin);
+}
+
+static void do_remove(char *name)
+{
+ snprintf(toybuf, sizeof(toybuf), "%s%s", TT.cdir, name);
+ if (unlink(toybuf))
+ error_exit("No crontab for '%s'", name);
+}
+
+static void update_crontab(char *src, char *dest)
+{
+ int fdin, fdout;
+
+ snprintf(toybuf, sizeof(toybuf), "%s%s", TT.cdir, dest);
+ fdout = xcreate(toybuf, O_WRONLY|O_CREAT|O_TRUNC, 0600);
+ fdin = xopen(src, O_RDONLY);
+ xsendfile(fdin, fdout);
+ xclose(fdin);
+
+ fchown(fdout, getuid(), geteuid());
+ xclose(fdout);
+}
+
+static void do_replace(char *name)
+{
+ char *fname = *toys.optargs ? *toys.optargs : "-";
+ char tname[] = "/tmp/crontab.XXXXXX";
+
+ if ((*fname == '-') && !*(fname+1)) {
+ int tfd = mkstemp(tname);
+
+ if (tfd < 0) perror_exit("mkstemp");
+ xsendfile(0, tfd);
+ xclose(tfd);
+ fname = tname;
+ }
+
+ if (parse_crontab(fname))
+ error_exit("errors in crontab file '%s', can't install.", fname);
+ update_crontab(fname, name);
+ unlink(tname);
+}
+
+static void do_edit(struct passwd *pwd)
+{
+ struct stat sb;
+ time_t mtime = 0;
+ int srcfd, destfd, status;
+ pid_t pid, cpid;
+ char tname[] = "/tmp/crontab.XXXXXX";
+
+ if ((destfd = mkstemp(tname)) < 0)
+ perror_exit("Can't open tmp file");
+
+ fchmod(destfd, 0666);
+ snprintf(toybuf, sizeof(toybuf), "%s%s", TT.cdir, pwd->pw_name);
+
+ if (!stat(toybuf, &sb)) { // file exists and have some content.
+ if (sb.st_size) {
+ srcfd = xopen(toybuf, O_RDONLY);
+ xsendfile(srcfd, destfd);
+ xclose(srcfd);
+ }
+ } else printf("No crontab for '%s'- using an empty one\n", pwd->pw_name);
+ xclose(destfd);
+
+ if (!stat(tname, &sb)) mtime = sb.st_mtime;
+
+RETRY:
+ if (!(pid = xfork())) {
+ char *prog = pwd->pw_shell;
+
+ xsetuser(pwd);
+ if (pwd->pw_uid) {
+ if (setenv("USER", pwd->pw_name, 1)) _exit(1);
+ if (setenv("LOGNAME", pwd->pw_name, 1)) _exit(1);
+ }
+ if (setenv("HOME", pwd->pw_dir, 1)) _exit(1);
+ if (setenv("SHELL",((!prog || !*prog) ? "/bin/sh" : prog), 1)) _exit(1);
+
+ if (!(prog = getenv("VISUAL"))) {
+ if (!(prog = getenv("EDITOR")))
+ prog = "vi";
+ }
+ execlp(prog, prog, tname, (char *) NULL);
+ perror_exit("can't execute '%s'", prog);
+ }
+
+ // Parent Process.
+ do {
+ cpid = waitpid(pid, &status, 0);
+ } while ((cpid == -1) && (errno == EINTR));
+
+ if (!stat(tname, &sb) && (mtime == sb.st_mtime)) {
+ printf("%s: no changes made to crontab\n", toys.which->name);
+ unlink(tname);
+ return;
+ }
+ printf("%s: installing new crontab\n", toys.which->name);
+ if (parse_crontab(tname)) {
+ snprintf(toybuf, sizeof(toybuf), "errors in crontab file, can't install.\n"
+ "Do you want to retry the same edit? ");
+ if (!yesno(toybuf, 0)) {
+ error_msg("edits left in '%s'", tname);
+ return;
+ }
+ goto RETRY;
+ }
+ // parsing of crontab success; update the crontab.
+ update_crontab(tname, pwd->pw_name);
+ unlink(tname);
+}
+
+void crontab_main(void)
+{
+ struct passwd *pwd = NULL;
+ long FLAG_elr = toys.optflags & (FLAG_e|FLAG_l|FLAG_r);
+
+ if (TT.cdir && (TT.cdir[strlen(TT.cdir)-1] != '/'))
+ TT.cdir = xmprintf("%s/", TT.cdir);
+ if (!TT.cdir) TT.cdir = xstrdup("/var/spool/cron/crontabs/");
+
+ if (toys.optflags & FLAG_u) {
+ if (getuid()) error_exit("must be privileged to use -u");
+ pwd = xgetpwnam(TT.user);
+ } else pwd = xgetpwuid(getuid());
+
+ if (!toys.optc) {
+ if (!FLAG_elr) {
+ if (toys.optflags & FLAG_u) {
+ toys.exithelp++;
+ error_exit("file name must be specified for replace");
+ }
+ do_replace(pwd->pw_name);
+ }
+ else if (toys.optflags & FLAG_e) do_edit(pwd);
+ else if (toys.optflags & FLAG_l) do_list(pwd->pw_name);
+ else if (toys.optflags & FLAG_r) do_remove(pwd->pw_name);
+ } else {
+ if (FLAG_elr) {
+ toys.exithelp++;
+ error_exit("no arguments permitted after this option");
+ }
+ do_replace(pwd->pw_name);
+ }
+ if (!(toys.optflags & FLAG_c)) free(TT.cdir);
+}