mdw@git.distorted.org.uk Git - dpkg/blob - lib/dpkg/string.c

   1 /*
   2  * libdpkg - Debian packaging suite library routines
   3  * string.c - string handling routines
   4  *
   5  * Copyright © 1995 Ian Jackson <ijackson@chiark.greenend.org.uk>
   6  * Copyright © 2008-2015 Guillem Jover <guillem@debian.org>
   7  *
   8  * This is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  20  */
  21
  22 #include <config.h>
  23 #include <compat.h>
  24
  25 #include <string.h>
  26
  27 #include <dpkg/c-ctype.h>
  28 #include <dpkg/string.h>
  29 #include <dpkg/dpkg.h>
  30
  31 /**
  32  * Match the end of a string.
  33  *
  34  * @param str The string.
  35  * @param end The end to match in str.
  36  *
  37  * @return Whether the string was matched at the end.
  38  */
  39 bool
  40 str_match_end(const char *str, const char *end)
  41 {
  42         size_t str_len = strlen(str);
  43         size_t end_len = strlen(end);
  44         const char *str_end = str + str_len - end_len;
  45
  46         if (str_len >= end_len && strcmp(str_end, end) == 0)
  47                 return true;
  48         else
  49                 return false;
  50 }
  51
  52 /**
  53  * Print formatted output to an allocated string.
  54  *
  55  * @param fmt The format string.
  56  * @param ... The format arguments.
  57  *
  58  * @return The new allocated formatted output string (never NULL).
  59  */
  60 char *
  61 str_fmt(const char *fmt, ...)
  62 {
  63         va_list args;
  64         char *str;
  65
  66         va_start(args, fmt);
  67         m_vasprintf(&str, fmt, args);
  68         va_end(args);
  69
  70         return str;
  71 }
  72
  73 /**
  74  * Escape format characters from a string.
  75  *
  76  * @param dst The destination string.
  77  * @param src The source string.
  78  * @param n The size of the destination buffer.
  79  *
  80  * @return The end of the destination string.
  81  */
  82 char *
  83 str_escape_fmt(char *dst, const char *src, size_t n)
  84 {
  85         char *d = dst;
  86         const char *s = src;
  87
  88         if (n == 0)
  89                 return d;
  90
  91         while (*s) {
  92                 if (*s == '%') {
  93                         if (n-- <= 2)
  94                                 break;
  95                         *d++ = '%';
  96                 }
  97                 if (n-- <= 1)
  98                         break;
  99                 *d++ = *s++;
 100         }
 101
 102         *d = '\0';
 103
 104         return d;
 105 }
 106
 107 /**
 108  * Quote shell metacharacters in a string.
 109  *
 110  * This function allows passing strings to commands without splitting the
 111  * arguments, like in system(3)
 112  *
 113  * @param src The source string to escape.
 114  *
 115  * @return The new allocated string (never NULL).
 116  */
 117 char *
 118 str_quote_meta(const char *src)
 119 {
 120         char *new_dst, *dst;
 121
 122         new_dst = dst = m_malloc(strlen(src) * 2);
 123
 124         while (*src) {
 125                 if (!c_isdigit(*src) && !c_isalpha(*src))
 126                         *dst++ = '\\';
 127
 128                 *dst++ = *src++;
 129         }
 130
 131         *dst = '\0';
 132
 133         return new_dst;
 134 }
 135
 136 /**
 137  * Check and strip possible surrounding quotes in string.
 138  *
 139  * @param str The string to act on.
 140  *
 141  * @return A pointer to str or NULL if the quotes were unbalanced.
 142  */
 143 char *
 144 str_strip_quotes(char *str)
 145 {
 146         if (str[0] == '"' || str[0] == '\'') {
 147                 size_t str_len = strlen(str);
 148
 149                 if (str[0] != str[str_len - 1])
 150                         return NULL;
 151
 152                 /* Remove surrounding quotes. */
 153                 str[str_len - 1] = '\0';
 154                 str++;
 155         }
 156
 157         return str;
 158 }