Error handling in Bash

Use a trap!

tempfiles=( )
cleanup() {
  rm -f "${tempfiles[@]}"
}
trap cleanup 0

error() {
  local parent_lineno="$1"
  local message="$2"
  local code="${3:-1}"
  if [[ -n "$message" ]] ; then
    echo "Error on or near line ${parent_lineno}: ${message}; exiting with status ${code}"
  else
    echo "Error on or near line ${parent_lineno}; exiting with status ${code}"
  fi
  exit "${code}"
}
trap 'error ${LINENO}' ERR

…then, whenever you create a temporary file:

temp_foo="$(mktemp -t foobar.XXXXXX)"
tempfiles+=( "$temp_foo" )

and $temp_foo will be deleted on exit, and the current line number will be printed. (set -e will likewise give you exit-on-error behavior, though it comes with serious caveats and weakens code’s predictability and portability).

You can either let the trap call error for you (in which case it uses the default exit code of 1 and no message) or call it yourself and provide explicit values; for instance:

error ${LINENO} "the foobar failed" 2

will exit with status 2, and give an explicit message.

Related Posts:

  1. How do I tell if a regular file does not exist in Bash?
  2. How do I parse command line arguments in Bash?
  3. How can I declare and use Boolean variables in a shell script?
  4. How can I declare and use Boolean variables in a shell script?
  5. Bash scripting missing ‘]’
  6. How do I compare two string variables in an ‘if’ statement in Bash?
  7. Shell script not running, command not found
  8. How to determine if a bash variable is empty?
  9. What is the difference between double and single square brackets in bash?
  10. How to make bash scripts print out every command before it executes?
  11. What does passing the -xe parameters to /bin/bash do
  12. How do I pause my shell script for a second before continuing?
  13. Cp: target is not a directory
  14. How do I split a string on a delimiter in Bash?
  15. How to create a file in Linux from terminal window? [closed]
  16. In the shell, what does ” 2>&1 ” mean?
  17. What is the preferred Bash shebang?
  18. How to compare strings in Bash
  19. How to decode Seagate’s hard drive date code in a Bash script
  20. What does export PS1=”\[\033[36m\]\u\[\033[m\]@\[\033[32m\]\h:\[\033[33;1m\]\w\[\033[m\]\$ ” mean in MacOS’ bash Terminal?
  21. How do I use a regex in a shell script?
  22. How do I execute a bash script in Terminal?
  23. How to make “if not true condition”?
  24. Multi-line string with extra space (preserved indentation)
  25. Bash script and /bin/bash^M: bad interpreter: No such file or directory
  26. An “and” operator for an “if” statement in Bash
  27. ‘\r’: command not found – .bashrc / .bash_profile [duplicate]
  28. How can I check if a directory exists in a Bash shell script?
  29. Echo newline in Bash prints literal \n
  30. Echo newline in Bash prints literal \n
  31. An “and” operator for an “if” statement in Bash
  32. What is the meaning of 2 in 2> /dev/null
  33. How to reload .bash_profile from the command line?
  34. What is the purpose of “&&” in a shell command?
  35. Replace one substring for another string in shell script
  36. Parsing JSON with Unix tools
  37. “[ ]” vs. “[[ ]]” in Bash shell
  38. How do I split a string on a delimiter in Bash?
  39. Cannot use mkdir in home directory: permission denied (Linux Lubuntu)
  40. Using find command in bash script
  41. Return value in a Bash function
  42. Emulating a do-while loop in Bash
  43. How to change the output color of echo in Linux
  44. Delete all local git branches
  45. How can I get the source directory of a Bash script from within the script itself?
  46. cp: missing destination file operand after
  47. BASH Syntax error near unexpected token ‘done’
  48. Shell: How to call one shell script from another shell script?
  49. bash assign default value
  50. What does -z mean in Bash?
  51. find: missing argument to -exec
  52. echo that outputs to stderr
  53. How to escape single quotes within single quoted strings
  54. Grep ‘binary file matches’. How to get normal grep output?
  55. Is there a TRY CATCH command in Bash
  56. Simple logical operators in Bash
  57. Bash if statement with multiple conditions throws an error
  58. Laravel PHP Command Not Found
  59. Getting an “ambiguous redirect” error
  60. Bash syntax error: unexpected end of file
  61. How to convert a string to lower case in Bash?
  62. Binary Data Posting with curl
  63. Difference between return and exit in Bash functions
  64. How to modify a global variable within a function in bash?
  65. How to modify a global variable within a function in bash?
  66. Bash script: bad interpreter
  67. How do I automatically restart a Minecraft Spigot server in the event of a crash or /stop when using screen?
  68. How do I remove the file suffix and path portion from a path string in Bash?
  69. Sorting data based on second column of a file
  70. Using SED with wildcard
  71. How do I add a newline using printf?
  72. zip error – Nothing to do
  73. How to remove last n characters from a string in Bash?
  74. How can I check if a program exists from a Bash script?
  75. Bash command to sum a column of numbers
  76. Meaning of “[: too many arguments” error from if [] (square brackets)
  77. Is there anything in Zsh like .bash_profile?
  78. How to split one string into multiple strings separated by at least one space in bash shell?
  79. Running programs in parallel using xargs
  80. “Error installing rails” because “extconf.rb failed” on Ubuntu 18.04
  81. How to output a multiline string in Bash?
  82. Make a Bash alias that takes a parameter?
  83. Copy multiple files from one directory to another from Linux shell
  84. How to ssh from within a bash script?
  85. How can I do a recursive find/replace of a string with awk or sed?
  86. bash : cd : too many arguments
  87. Bash mkdir and subfolders
  88. What is a simple explanation for how pipes work in Bash?
  89. Integer expression expected error in shell script
  90. How do I know the script file name in a Bash script?
  91. Error when using ‘sed’ with ‘find’ command on OS X: “invalid command code .”
  92. How to create a UUID in bash?
  93. Check if array is empty in Bash
  94. What is “-bash: !”: event not found”
  95. Run an interactive bash subshell with initial commands without returning to the (“super”) shell immediately
  96. bash: print stderr in red color
  97. Clean way to write complex multi-line string to a variable
  98. How can I fully log all bash scripts actions?
  99. How can I run arbitrarily complex command using sudo over ssh?
  100. Standard place for user defined bash_completion.d scripts?

Leave a Comment