1explain_execlp(3)          Library Functions Manual          explain_execlp(3)
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NAME

6       explain_execlp - explain execlp(3) errors
7

SYNOPSIS

9       #include <libexplain/execlp.h>
10       const char *explain_execlp(, ...);
11       const char *explain_errno_execlp(int errnum, , ...);
12       void explain_message_execlp(char *message, int message_size, , ...);
13       void explain_message_errno_execlp(char *message, int message_size, int
14       errnum, , ...);
15

DESCRIPTION

17       These functions may be used to obtain explanations for errors  returned
18       by the execlp(3) system call.
19
20   explain_execlp
21       const char *explain_execlp(, ...);
22
23       The  explain_execlp  function  is  used  to obtain an explanation of an
24       error returned by the execlp(3) system call. The least the message will
25       contain  is  the  value of strerror(errno), but usually it will do much
26       better, and indicate the underlying cause in more detail.
27
28       The errno global variable will be used to obtain the error value to  be
29       decoded.
30
31       Returns:
32               The message explaining the error. This message buffer is shared
33               by all libexplain functions which do not  supply  a  buffer  in
34               their argument list.  This will be overwritten by the next call
35               to any libexplain function which shares this buffer,  including
36               other threads.
37
38       Note: This function is not thread safe, because it shares a return buf‐
39       fer across all threads, and many other functions in this library.
40
41       Example: This function is intended to be used in a fashion  similar  to
42       the following example:
43              if (execlp() < 0)
44              {
45                  fprintf(stderr, "%s\n", explain_execlp());
46                  exit(EXIT_FAILURE);
47              }
48
49       The  above  code  example is available pre‐packaged as the explain_exe‐
50       clp_or_die(3) function.
51
52   explain_errno_execlp
53       const char *explain_errno_execlp(int errnum, , ...);
54
55       The explain_errno_execlp function is used to obtain an  explanation  of
56       an  error  returned by the execlp(3) system call. The least the message
57       will contain is the value of strerror(errno), but usually  it  will  do
58       much better, and indicate the underlying cause in more detail.
59
60       errnum  The  error value to be decoded, usually obtained from the errno
61               global variable just before this function is  called.  This  is
62               necessary  if you need to call any code between the system call
63               to be explained and this function, because many libc  functions
64               will alter the value of errno.
65
66       Returns:
67               The message explaining the error. This message buffer is shared
68               by all libexplain functions which do not  supply  a  buffer  in
69               their argument list.  This will be overwritten by the next call
70               to any libexplain function which shares this buffer,  including
71               other threads.
72
73       Note: This function is not thread safe, because it shares a return buf‐
74       fer across all threads, and many other functions in this library.
75
76       Example: This function is intended to be used in a fashion  similar  to
77       the following example:
78              if (execlp() < 0)
79              {
80                  int err = errno;
81                  fprintf(stderr, "%s\n", explain_errno_execlp(err, ));
82                  exit(EXIT_FAILURE);
83              }
84
85       The  above  code  example is available pre‐packaged as the explain_exe‐
86       clp_or_die(3) function.
87
88   explain_message_execlp
89       void explain_message_execlp(char *message, int message_size, , ...);
90
91       The explain_message_execlp function is used to obtain an explanation of
92       an  error  returned by the execlp(3) system call. The least the message
93       will contain is the value of strerror(errno), but usually  it  will  do
94       much better, and indicate the underlying cause in more detail.
95
96       The  errno global variable will be used to obtain the error value to be
97       decoded.
98
99       message The location in which to store the returned message. If a suit‐
100               able message return buffer is supplied, this function is thread
101               safe.
102
103       message_size
104               The size in bytes  of  the  location  in  which  to  store  the
105               returned message.
106
107       Example:  This  function is intended to be used in a fashion similar to
108       the following example:
109              if (execlp() < 0)
110              {
111                  char message[3000];
112                  explain_message_execlp(message, sizeof(message), );
113                  fprintf(stderr, "%s\n", message);
114                  exit(EXIT_FAILURE);
115              }
116
117       The above code example is available pre‐packaged  as  the  explain_exe‐
118       clp_or_die(3) function.
119
120   explain_message_errno_execlp
121       void explain_message_errno_execlp(char *message, int message_size, int
122       errnum, , ...);
123
124       The explain_message_errno_execlp function is used to obtain an explana‐
125       tion  of  an error returned by the execlp(3) system call. The least the
126       message will contain is the value of strerror(errno),  but  usually  it
127       will do much better, and indicate the underlying cause in more detail.
128
129       message The location in which to store the returned message. If a suit‐
130               able message return buffer is supplied, this function is thread
131               safe.
132
133       message_size
134               The  size  in  bytes  of  the  location  in  which to store the
135               returned message.
136
137       errnum  The error value to be decoded, usually obtained from the  errno
138               global  variable  just  before this function is called. This is
139               necessary if you need to call any code between the system  call
140               to  be explained and this function, because many libc functions
141               will alter the value of errno.
142
143       Example: This function is intended to be used in a fashion  similar  to
144       the following example:
145              if (execlp() < 0)
146              {
147                  int err = errno;
148                  char message[3000];
149                  explain_message_errno_execlp(message, sizeof(message), err,
150                  );
151                  fprintf(stderr, "%s\n", message);
152                  exit(EXIT_FAILURE);
153              }
154
155       The above code example is available pre‐packaged  as  the  explain_exe‐
156       clp_or_die(3) function.
157

SEE ALSO

159       execlp(3)
160               execute a file
161
162       explain_execlp_or_die(3)
163               execute a file and report errors
164
166       libexplain version 0.40
167       Copyright (C) 2009 Peter Miller
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171                                                             explain_execlp(3)
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