1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2010 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #ifndef _OFMT_H 28 #define _OFMT_H 29 30 /* 31 * Data structures and routines for printing output. 32 * 33 * All output is assumed to be in a columnar format, where each column 34 * represents a field to be printed out. Multiple fields in parsable output 35 * are separated by ':', with the ':' character itself escaped by a \ 36 * (e.g., IPv6 addresses may be printed as "fe80\:\:1"); single field output 37 * is printed as-is. 38 * In multiline mode, every [field,value] pair is printed in a line of 39 * its own, thus: "field: value". 40 * 41 * The caller must open a handle for each set of fields to be printed by 42 * invoking ofmt_open(). The invocation to ofmt_open must provide the list of 43 * supported fields, along with formatting information (e.g., field width), and 44 * a pointer to a callback function that can provide a string representation of 45 * the value to be printed out. The set of supported fields must be a NULL 46 * terminated array of type ofmt_field_t *ofields[]. The contents of the 47 * ofmt_field_t structure are used to construct the string that is emitted by 48 * ofmt_print(), and the interpretation of these contents is described with the 49 * semantics of ofmt_print() below. 50 * 51 * In addition, the call to ofmt_open() should provide a comma-separated 52 * list of the fields, char *fields_str, that have been selected for output 53 * (typically the string passed to -o in the command-line). The caller may 54 * also specify machine-parsable mode by specifying OFMT_PARSABLE in the oflags 55 * argument. Specifying a null or empty fields_str in the machine-parsable mode 56 * will result in a returned error value of OFMT_EPARSENONE. An attempt to 57 * create a handle in machine-parsable mode with the fields_str set to "all" 58 * will result in a returned error value of OFMT_EPARSEALL. In human-friendly 59 * (non machine-parsable) mode, a NULL fields_str, or a value of "all" for 60 * fields_str, is treated as a request to print all allowable fields that fit 61 * other applicable constraints. 62 * To achieve multiline mode, OFMT_MULTILINE needs to be specified in oflags. 63 * Specifying both OFMT_MULTILINE and OFMT_PARSABLE will result in 64 * OFMT_EPARSEMULTI. 65 * 66 * Thus a typical invocation to open the ofmt_handle would be: 67 * 68 * ofmt_handle_t ofmt; 69 * ofmt_status_t ofmt_err; 70 * 71 * ofmt_err = ofmt_open(fields_str, ofields, oflags, maxcols, &ofmt); 72 * 73 * where ofields is an array of the form: 74 * 75 * static ofmt_field_t ofields[] = { 76 * {<name>, <field width>, <id>, <callback> }, 77 * : 78 * {<name>, <field width>, <id>, <callback> }, 79 * {NULL, 0, 0, NULL}} 80 * 81 * <callback> is the application-specified function that provides a string 82 * representation of the value to be printed for the field. The calling 83 * application may provide unique values of <id> that will be passed back to 84 * <callback>, allowing a single <callback> to be shared between multiple 85 * fields in ofields[] with the value of <id> identifying the field that 86 * triggers the callback. 87 * 88 * If successful, ofmt_open() will return OFMT_SUCCESS, with a non-null 89 * ofmt_handle. The function returns a failure code otherwise, and more 90 * information about the type of failure can be obtained by calling 91 * ofmt_strerror() 92 * 93 * In order to print a row of output, the calling application should invoke 94 * 95 * ofmt_print(ofmt_handle, cbarg); 96 * 97 * where 'cbarg' points at the arguments to be passed to the <callback> 98 * function for each column in the row. The call to ofmt_print() will then 99 * result in the <callback> function of each selected field from ofields[] 100 * invoked with cbarg embedded in the ofmt_arg as 101 * 102 * (*callback)(ofmt_arg_t *ofmt_arg, char *buf, uint_t bufsize) 103 * 104 * Columns selected for output are identified by a match between the of_name 105 * value in the ofmt_field_t and the fields_str requested. For each selected 106 * column, the callback function (*of_cb)() is invoked, and is passed the of_id 107 * value from the ofmt_field_t structure for the field. 108 * 109 * The interpretation of the of_id field is completely private to the caller, 110 * and can be optionally used by the callback function as a cookie 111 * to identify the field being printed when a single callback function is 112 * shared between multiple ofmt_field_t entries. 113 * 114 * The callback function should fill `buf' with the string to be printed for 115 * the field using the data in cbarg. 116 * 117 * The calling application should invoke ofmt_close(ofmt_handle) to free up any 118 * resources allocated for the handle after all printing is completed. 119 * 120 * The printing library computes the current size of the output window when the 121 * handle is first created. If the caller wishes to adjust the window size 122 * after the handle has been created (e.g., on the reception of SIGWINCH by the 123 * caller), the function ofmt_update_winsize(handle) may be called. 124 */ 125 126 #ifdef __cplusplus 127 extern "C" { 128 #endif 129 130 /* 131 * Recommended buffer size for buffers passed, for example, to ofmt_strerror(). 132 */ 133 #define OFMT_BUFSIZE 256 134 135 typedef enum { 136 OFMT_SUCCESS = 0, 137 OFMT_ENOMEM, /* out of memory */ 138 OFMT_EBADFIELDS, /* one or more bad fields with good fields */ 139 OFMT_ENOFIELDS, /* no valid output fields */ 140 OFMT_EPARSEALL, /* 'all' invalid in parsable mode */ 141 OFMT_EPARSENONE, /* output fields missing in parsable mode */ 142 OFMT_EPARSEWRAP, /* parsable mode incompatible with wrap mode */ 143 OFMT_ENOTEMPLATE, /* no template provided for fields */ 144 OFMT_EPARSEMULTI /* parsable and multiline don't mix */ 145 } ofmt_status_t; 146 147 /* 148 * The callback function for each field is invoked with a pointer to the 149 * ofmt_arg_t structure that contains the <id> registered by the application 150 * for that field, and the cbarg used by the application when invoking 151 * ofmt_output(). 152 */ 153 typedef struct ofmt_arg_s { 154 uint_t ofmt_id; 155 uint_t ofmt_width; 156 uint_t ofmt_index; 157 void *ofmt_cbarg; 158 } ofmt_arg_t; 159 160 /* 161 * ofmt callback function that provides a string representation of the value to 162 * be printed for the field. 163 */ 164 typedef boolean_t ofmt_cb_t(ofmt_arg_t *, char *, uint_t); 165 typedef struct ofmt_field_s { 166 char *of_name; /* column name */ 167 uint_t of_width; /* output column width */ 168 uint_t of_id; /* implementation specific cookie */ 169 ofmt_cb_t *of_cb; /* callback function defined by caller */ 170 } ofmt_field_t; 171 172 /* 173 * ofmt_open() must be called to create the ofmt_handle_t; Resources allocated 174 * for the handle are freed by ofmt_close(); 175 */ 176 typedef struct ofmt_state_s *ofmt_handle_t; 177 extern ofmt_status_t ofmt_open(const char *, const ofmt_field_t *, uint_t, 178 uint_t, ofmt_handle_t *); 179 180 #define OFMT_PARSABLE 0x00000001 /* machine parsable mode */ 181 #define OFMT_WRAP 0x00000002 /* wrap output if field width is exceeded */ 182 #define OFMT_MULTILINE 0x00000004 /* "long" output: "name: value" lines */ 183 #define OFMT_RIGHTJUST 0x00000008 /* right justified output */ 184 185 /* 186 * ofmt_close() must be called to free resources associated 187 * with the ofmt_handle_t 188 */ 189 extern void ofmt_close(ofmt_handle_t); 190 191 /* 192 * ofmt_print() emits one row of output 193 */ 194 extern void ofmt_print(ofmt_handle_t, void *); 195 196 /* 197 * ofmt_update_winsize() updates the window size information for ofmt_handle_t 198 */ 199 extern void ofmt_update_winsize(ofmt_handle_t); 200 201 /* 202 * ofmt_strerror() provides error diagnostics in the buffer that it is passed. 203 */ 204 extern char *ofmt_strerror(ofmt_handle_t, ofmt_status_t, char *, uint_t); 205 206 #ifdef __cplusplus 207 } 208 #endif 209 210 #endif /* _OFMT_H */ 211