changeset 1542:fd587c7872a9

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.
author Ashwini Sharma
date Thu, 30 Oct 2014 18:36:09 -0500
parents 28b0987d4952
children ad6b2f0e566b
files toys/pending/crontab.c toys/pending/tr.c
diffstat 2 files changed, 634 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toys/pending/crontab.c	Thu Oct 30 18:36:09 2014 -0500
@@ -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);
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toys/pending/tr.c	Thu Oct 30 18:36:09 2014 -0500
@@ -0,0 +1,268 @@
+/* tr.c - translate or delete characters
+ *
+ * Copyright 2014 Sandeep Sharma <sandeep.jack2756@gmail.com>
+ *
+ * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/tr.html
+
+USE_TR(NEWTOY(tr, "^>2<1Ccsd[+cC]", TOYFLAG_USR|TOYFLAG_BIN))
+
+config TR
+  bool "tr"
+  default n
+  help
+    usage: tr [-cds] SET1 [SET2]
+
+    Translate, squeeze, or delete characters from stdin, writing to stdout
+
+    -c/-C  Take complement of SET1
+    -d     Delete input characters coded SET1
+    -s     Squeeze multiple output characters of SET2 into one character
+*/
+
+#define FOR_tr
+#include "toys.h"
+
+GLOBALS(
+  short map[256]; //map of chars
+  int len1, len2;
+)
+
+enum {
+  class_alpha, class_alnum, class_digit,
+  class_lower,class_upper,class_space,class_blank,
+  class_punct,class_cntrl,class_xdigit,class_invalid
+};
+
+static void map_translation(char *set1 , char *set2)
+{
+  int i = TT.len1, k = 0;
+
+  if (toys.optflags & FLAG_d)
+    for (; i; i--, k++) TT.map[set1[k]] = set1[k]|0x100; //set delete bit
+
+  if (toys.optflags & FLAG_s) {
+    for (i = TT.len1, k = 0; i; i--, k++)
+      TT.map[set1[k]] = TT.map[set1[k]]|0x200;
+    for (i = TT.len2, k = 0; i; i--, k++)
+      TT.map[set2[k]] = TT.map[set2[k]]|0x200;
+  }
+  i = k = 0;
+  while (!(toys.optflags & FLAG_d) && set2 && TT.len1--) { //ignore set2 if -d present
+    TT.map[set1[i]] = ((TT.map[set1[i]] & 0xFF00) | set2[k]);
+    if (set2[k + 1]) k++;
+    i++;
+  }
+}
+
+static int handle_escape_char(char **esc_val) //taken from printf
+{
+  char *ptr = *esc_val;
+  int esc_length = 0;
+  unsigned  base = 0, num = 0, result = 0, count = 0;
+
+  if (*ptr == 'x') {
+    ptr++;
+    esc_length++;
+    base = 16;
+  } else if (isdigit(*ptr)) base = 8;
+
+  while (esc_length < 3 && base) {
+    num = tolower(*ptr) - '0';
+    if (num > 10) num += ('0' - 'a' + 10);
+    if (num >= base) {
+      if (base == 16) {
+        esc_length--;
+        if (!esc_length) {// Invalid hex value eg. /xvd, print as it is /xvd
+          result = '\\';
+          ptr--;
+        }
+      }
+      break;
+    }
+    esc_length++;
+    count = result = (count * base) + num;
+    ptr++;
+  }
+  if (base) {
+    ptr--;
+    *esc_val = ptr;
+    return (char)result;
+  } else {
+    switch (*ptr) {
+      case 'n':  result = '\n'; break;
+      case 't':  result = '\t'; break;
+      case 'e':  result = (char)27; break;
+      case 'b':  result = '\b'; break;
+      case 'a':  result = '\a'; break;
+      case 'f':  result = '\f'; break;
+      case 'v':  result = '\v'; break;
+      case 'r':  result = '\r'; break;
+      case '\\': result = '\\'; break;
+      default :
+        result = '\\';
+        ptr--; // Let pointer pointing to / we will increment after returning.
+        break;
+    }
+  }
+  *esc_val = ptr;
+  return (char)result;
+}
+
+static int find_class(char *class_name)
+{
+  int i;
+  static char *class[] = {
+    "[:alpha:]","[:alnum:]","[:digit:]",
+    "[:lower:]","[:upper:]","[:space:]",
+    "[:blank:]","[:punct:]","[:cntrl:]",
+    "[:xdigit:]","NULL"
+  };
+
+  for (i = 0; i != class_invalid; i++) {
+    if (!memcmp(class_name, class[i], (class_name[0] == 'x')?10:9)) break;
+  }
+  return i;
+}
+
+static char *expand_set(char *arg, int *len)
+{
+  int i = 0, j, k, size = 256;
+  char *set = xzalloc(size*sizeof(char));
+
+  while (*arg) {
+
+    if (i >= size) {
+      size += 256;
+      set = xrealloc(set, size);
+    }
+    if (*arg == '\\') {
+      arg++;
+      set[i++] = (int)handle_escape_char(&arg);
+      arg++;
+      continue;
+    }
+    if (arg[1] == '-') {
+      if (arg[2] == '\0') goto save;
+      j = arg[0];
+      k = arg[2];
+      if (j > k) perror_exit("reverse colating order");
+      while (j <= k) set[i++] = j++;
+      arg += 3;
+      continue;
+    }
+    if (arg[0] == '[' && arg[1] == ':') {
+
+      if ((j = find_class(arg)) == class_invalid) goto save;
+
+      if ((j == class_alpha) || (j == class_upper) || (j == class_alnum)) {
+      for (k = 'A'; k <= 'Z'; k++) set[i++] = k;
+      }
+      if ((j == class_alpha) || (j == class_lower) || (j == class_alnum)) {
+        for (k = 'a'; k <= 'z'; k++) set[i++] = k;
+      }
+      if ((j == class_alnum) || (j == class_digit) || (j == class_xdigit)) {
+        for (k = '0'; k <= '9'; k++) set[i++] = k;
+      }
+      if (j == class_space || j == class_blank) {
+        set[i++] = '\t';
+        if (j == class_space) {
+          set[i++] = '\n';
+          set[i++] = '\f';
+          set[i++] = '\r';
+          set[i++] = '\v';
+        }
+        set[i++] = ' ';
+      }
+      if (j == class_punct) {
+        for (k = 0; k <= 255; k++)
+          if (ispunct(k)) set[i++] = k;
+      }
+      if (j == class_cntrl) {
+        for (k = 0; k <= 255; k++)
+          if (iscntrl(k)) set[i++] = k;
+      }
+      if (j == class_xdigit) {
+        for (k = 'A'; k <= 'F'; k++) {
+          set[i + 6] = k | 0x20;
+          set[i++] = k;
+        }
+        i += 6;
+        arg += 10;
+        continue;
+      }
+
+      arg += 9; //never here for class_xdigit.
+      continue;
+    }
+    if (arg[0] == '[' && arg[1] == '=') { //[=char=] only
+      arg += 2;
+      if (*arg) set[i++] = *arg;
+      if (!arg[1] || arg[1] != '=' || arg[2] != ']')
+        error_exit("bad equiv class");
+      continue;
+    }
+save:
+    set[i++] = *arg++;
+  }
+  *len = i;
+  return set;
+}
+
+static void print_map(char *set1, char *set2)
+{
+  int r = 0, i, prev_char = -1;
+
+  while (1)
+  {
+    i = 0;
+    r = read(STDIN_FILENO, (toybuf), sizeof(toybuf));
+    if (!r) break;
+    for (;r > i;i++) {
+
+      if ((toys.optflags & FLAG_d) && (TT.map[(int)toybuf[i]] & 0x100)) continue;
+      if (toys.optflags & FLAG_s) {
+        if ((TT.map[(int)toybuf[i]] & 0x200) &&
+            (prev_char == TT.map[(int)toybuf[i]])) {
+          continue;
+        }
+      }
+      xputc(TT.map[(int)toybuf[i]] & 0xFF);
+      prev_char = TT.map[(int)toybuf[i]];
+      fflush(stdout);
+    }
+  }
+}
+
+static void do_complement(char **set)
+{
+  int i, j;
+  char *comp = xmalloc(256);
+
+  for (i = 0, j = 0;i < 256; i++) {
+    if (memchr(*set, i, TT.len1)) continue;
+    else comp[j++] = (char)i;
+  }
+  free(*set);
+  TT.len1 = j;
+  *set = comp;
+}
+
+void tr_main(void)
+{
+  char *set1, *set2 = NULL;
+  int i;
+
+  for (i = 0; i < 256; i++) TT.map[i] = i; //init map
+
+  set1 = expand_set(toys.optargs[0], &TT.len1);
+  if (toys.optflags & FLAG_c) do_complement(&set1);
+  if (toys.optargs[1]) {
+    if (toys.optargs[1][0] == '\0') error_exit("set2 can't be empty string");
+    set2 = expand_set(toys.optargs[1], &TT.len2);
+  }
+  map_translation(set1, set2);
+
+  print_map(set1, set2);
+  free(set1);
+  free(set2);
+}