1 | /* vi: set sw=4 ts=4: */
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2 | /*
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3 | * cut.c - minimalist version of cut
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4 | *
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5 | * Copyright (C) 1999,2000,2001 by Lineo, inc.
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6 | * Written by Mark Whitley <markw@codepoet.org>
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7 | * debloated by Bernhard Reutner-Fischer
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8 | *
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9 | * Licensed under GPLv2 or later, see file LICENSE in this source tree.
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10 | */
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11 |
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12 | //usage:#define cut_trivial_usage
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13 | //usage: "[OPTIONS] [FILE]..."
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14 | //usage:#define cut_full_usage "\n\n"
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15 | //usage: "Print selected fields from each input FILE to stdout\n"
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16 | //usage: "\n -b LIST Output only bytes from LIST"
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17 | //usage: "\n -c LIST Output only characters from LIST"
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18 | //usage: "\n -d CHAR Use CHAR instead of tab as the field delimiter"
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19 | //usage: "\n -s Output only the lines containing delimiter"
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20 | //usage: "\n -f N Print only these fields"
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21 | //usage: "\n -n Ignored"
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22 | //usage:
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23 | //usage:#define cut_example_usage
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24 | //usage: "$ echo \"Hello world\" | cut -f 1 -d ' '\n"
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25 | //usage: "Hello\n"
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26 | //usage: "$ echo \"Hello world\" | cut -f 2 -d ' '\n"
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27 | //usage: "world\n"
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28 |
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29 | #include "libbb.h"
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30 |
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31 | /* This is a NOEXEC applet. Be very careful! */
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32 |
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33 |
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34 | /* option vars */
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35 | static const char optstring[] ALIGN1 = "b:c:f:d:sn";
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36 | #define CUT_OPT_BYTE_FLGS (1 << 0)
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37 | #define CUT_OPT_CHAR_FLGS (1 << 1)
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38 | #define CUT_OPT_FIELDS_FLGS (1 << 2)
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39 | #define CUT_OPT_DELIM_FLGS (1 << 3)
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40 | #define CUT_OPT_SUPPRESS_FLGS (1 << 4)
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41 |
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42 | struct cut_list {
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43 | int startpos;
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44 | int endpos;
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45 | };
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46 |
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47 | enum {
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48 | BOL = 0,
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49 | EOL = INT_MAX,
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50 | NON_RANGE = -1
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51 | };
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52 |
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53 | static int cmpfunc(const void *a, const void *b)
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54 | {
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55 | return (((struct cut_list *) a)->startpos -
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56 | ((struct cut_list *) b)->startpos);
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57 | }
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58 |
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59 | static void cut_file(FILE *file, char delim, const struct cut_list *cut_lists, unsigned nlists)
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60 | {
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61 | char *line;
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62 | unsigned linenum = 0; /* keep these zero-based to be consistent */
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63 |
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64 | /* go through every line in the file */
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65 | while ((line = xmalloc_fgetline(file)) != NULL) {
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66 |
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67 | /* set up a list so we can keep track of what's been printed */
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68 | int linelen = strlen(line);
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69 | char *printed = xzalloc(linelen + 1);
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70 | char *orig_line = line;
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71 | unsigned cl_pos = 0;
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72 | int spos;
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73 |
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74 | /* cut based on chars/bytes XXX: only works when sizeof(char) == byte */
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75 | if (option_mask32 & (CUT_OPT_CHAR_FLGS | CUT_OPT_BYTE_FLGS)) {
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76 | /* print the chars specified in each cut list */
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77 | for (; cl_pos < nlists; cl_pos++) {
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78 | spos = cut_lists[cl_pos].startpos;
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79 | while (spos < linelen) {
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80 | if (!printed[spos]) {
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81 | printed[spos] = 'X';
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82 | putchar(line[spos]);
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83 | }
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84 | spos++;
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85 | if (spos > cut_lists[cl_pos].endpos
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86 | /* NON_RANGE is -1, so if below is true,
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87 | * the above was true too (spos is >= 0) */
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88 | /* || cut_lists[cl_pos].endpos == NON_RANGE */
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89 | ) {
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90 | break;
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91 | }
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92 | }
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93 | }
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94 | } else if (delim == '\n') { /* cut by lines */
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95 | spos = cut_lists[cl_pos].startpos;
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96 |
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97 | /* get out if we have no more lists to process or if the lines
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98 | * are lower than what we're interested in */
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99 | if (((int)linenum < spos) || (cl_pos >= nlists))
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100 | goto next_line;
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101 |
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102 | /* if the line we're looking for is lower than the one we were
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103 | * passed, it means we displayed it already, so move on */
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104 | while (spos < (int)linenum) {
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105 | spos++;
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106 | /* go to the next list if we're at the end of this one */
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107 | if (spos > cut_lists[cl_pos].endpos
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108 | || cut_lists[cl_pos].endpos == NON_RANGE
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109 | ) {
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110 | cl_pos++;
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111 | /* get out if there's no more lists to process */
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112 | if (cl_pos >= nlists)
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113 | goto next_line;
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114 | spos = cut_lists[cl_pos].startpos;
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115 | /* get out if the current line is lower than the one
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116 | * we just became interested in */
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117 | if ((int)linenum < spos)
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118 | goto next_line;
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119 | }
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120 | }
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121 |
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122 | /* If we made it here, it means we've found the line we're
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123 | * looking for, so print it */
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124 | puts(line);
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125 | goto next_line;
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126 | } else { /* cut by fields */
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127 | int ndelim = -1; /* zero-based / one-based problem */
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128 | int nfields_printed = 0;
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129 | char *field = NULL;
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130 | char delimiter[2];
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131 |
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132 | delimiter[0] = delim;
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133 | delimiter[1] = 0;
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134 |
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135 | /* does this line contain any delimiters? */
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136 | if (strchr(line, delim) == NULL) {
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137 | if (!(option_mask32 & CUT_OPT_SUPPRESS_FLGS))
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138 | puts(line);
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139 | goto next_line;
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140 | }
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141 |
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142 | /* process each list on this line, for as long as we've got
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143 | * a line to process */
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144 | for (; cl_pos < nlists && line; cl_pos++) {
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145 | spos = cut_lists[cl_pos].startpos;
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146 | do {
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147 | /* find the field we're looking for */
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148 | while (line && ndelim < spos) {
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149 | field = strsep(&line, delimiter);
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150 | ndelim++;
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151 | }
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152 |
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153 | /* we found it, and it hasn't been printed yet */
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154 | if (field && ndelim == spos && !printed[ndelim]) {
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155 | /* if this isn't our first time through, we need to
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156 | * print the delimiter after the last field that was
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157 | * printed */
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158 | if (nfields_printed > 0)
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159 | putchar(delim);
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160 | fputs(field, stdout);
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161 | printed[ndelim] = 'X';
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162 | nfields_printed++; /* shouldn't overflow.. */
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163 | }
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164 |
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165 | spos++;
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166 |
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167 | /* keep going as long as we have a line to work with,
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168 | * this is a list, and we're not at the end of that
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169 | * list */
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170 | } while (spos <= cut_lists[cl_pos].endpos && line
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171 | && cut_lists[cl_pos].endpos != NON_RANGE);
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172 | }
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173 | }
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174 | /* if we printed anything at all, we need to finish it with a
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175 | * newline cuz we were handed a chomped line */
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176 | putchar('\n');
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177 | next_line:
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178 | linenum++;
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179 | free(printed);
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180 | free(orig_line);
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181 | }
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182 | }
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183 |
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184 | int cut_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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185 | int cut_main(int argc UNUSED_PARAM, char **argv)
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186 | {
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187 | /* growable array holding a series of lists */
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188 | struct cut_list *cut_lists = NULL;
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189 | unsigned nlists = 0; /* number of elements in above list */
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190 | char delim = '\t'; /* delimiter, default is tab */
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191 | char *sopt, *ltok;
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192 | unsigned opt;
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193 |
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194 | opt_complementary = "b--bcf:c--bcf:f--bcf";
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195 | opt = getopt32(argv, optstring, &sopt, &sopt, &sopt, <ok);
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196 | // argc -= optind;
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197 | argv += optind;
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198 | if (!(opt & (CUT_OPT_BYTE_FLGS | CUT_OPT_CHAR_FLGS | CUT_OPT_FIELDS_FLGS)))
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199 | bb_error_msg_and_die("expected a list of bytes, characters, or fields");
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200 |
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201 | if (opt & CUT_OPT_DELIM_FLGS) {
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202 | if (ltok[0] && ltok[1]) { /* more than 1 char? */
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203 | bb_error_msg_and_die("the delimiter must be a single character");
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204 | }
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205 | delim = ltok[0];
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206 | }
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207 |
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208 | /* non-field (char or byte) cutting has some special handling */
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209 | if (!(opt & CUT_OPT_FIELDS_FLGS)) {
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210 | static const char _op_on_field[] ALIGN1 = " only when operating on fields";
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211 |
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212 | if (opt & CUT_OPT_SUPPRESS_FLGS) {
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213 | bb_error_msg_and_die
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214 | ("suppressing non-delimited lines makes sense%s",
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215 | _op_on_field);
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216 | }
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217 | if (delim != '\t') {
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218 | bb_error_msg_and_die
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219 | ("a delimiter may be specified%s", _op_on_field);
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220 | }
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221 | }
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222 |
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223 | /*
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224 | * parse list and put values into startpos and endpos.
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225 | * valid list formats: N, N-, N-M, -M
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226 | * more than one list can be separated by commas
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227 | */
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228 | {
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229 | char *ntok;
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230 | int s = 0, e = 0;
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231 |
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232 | /* take apart the lists, one by one (they are separated with commas) */
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233 | while ((ltok = strsep(&sopt, ",")) != NULL) {
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234 |
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235 | /* it's actually legal to pass an empty list */
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236 | if (!ltok[0])
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237 | continue;
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238 |
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239 | /* get the start pos */
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240 | ntok = strsep(<ok, "-");
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241 | if (!ntok[0]) {
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242 | s = BOL;
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243 | } else {
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244 | s = xatoi_positive(ntok);
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245 | /* account for the fact that arrays are zero based, while
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246 | * the user expects the first char on the line to be char #1 */
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247 | if (s != 0)
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248 | s--;
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249 | }
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250 |
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251 | /* get the end pos */
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252 | if (ltok == NULL) {
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253 | e = NON_RANGE;
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254 | } else if (!ltok[0]) {
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255 | e = EOL;
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256 | } else {
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257 | e = xatoi_positive(ltok);
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258 | /* if the user specified and end position of 0,
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259 | * that means "til the end of the line" */
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260 | if (e == 0)
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261 | e = EOL;
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262 | e--; /* again, arrays are zero based, lines are 1 based */
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263 | if (e == s)
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264 | e = NON_RANGE;
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265 | }
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266 |
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267 | /* add the new list */
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268 | cut_lists = xrealloc_vector(cut_lists, 4, nlists);
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269 | /* NB: startpos is always >= 0,
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270 | * while endpos may be = NON_RANGE (-1) */
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271 | cut_lists[nlists].startpos = s;
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272 | cut_lists[nlists].endpos = e;
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273 | nlists++;
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274 | }
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275 |
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276 | /* make sure we got some cut positions out of all that */
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277 | if (nlists == 0)
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278 | bb_error_msg_and_die("missing list of positions");
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279 |
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280 | /* now that the lists are parsed, we need to sort them to make life
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281 | * easier on us when it comes time to print the chars / fields / lines
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282 | */
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283 | qsort(cut_lists, nlists, sizeof(cut_lists[0]), cmpfunc);
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284 | }
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285 |
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286 | {
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287 | int retval = EXIT_SUCCESS;
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288 |
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289 | if (!*argv)
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290 | *--argv = (char *)"-";
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291 |
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292 | do {
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293 | FILE *file = fopen_or_warn_stdin(*argv);
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294 | if (!file) {
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295 | retval = EXIT_FAILURE;
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296 | continue;
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297 | }
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298 | cut_file(file, delim, cut_lists, nlists);
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299 | fclose_if_not_stdin(file);
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300 | } while (*++argv);
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301 |
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302 | if (ENABLE_FEATURE_CLEAN_UP)
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303 | free(cut_lists);
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304 | fflush_stdout_and_exit(retval);
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305 | }
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306 | }
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