29 - diff will show the current time |
29 - diff will show the current time |
30 |
30 |
31 use hg diff | sed -e "s/\(+++ [a-zA-Z0-9_/.-]*\).*/\1/" \ |
31 use hg diff | sed -e "s/\(+++ [a-zA-Z0-9_/.-]*\).*/\1/" \ |
32 -e "s/\(--- [a-zA-Z0-9_/.-]*\).*/\1/" |
32 -e "s/\(--- [a-zA-Z0-9_/.-]*\).*/\1/" |
33 to strip dates |
33 to strip dates |
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34 |
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35 You also need to be careful that the tests are portable from one platform |
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36 to another. You're probably working on Linux, where the GNU toolchain has |
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37 more (or different) functionality than on MacOS, *BSD, Solaris, AIX, etc. |
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38 While testing on all platforms is the only sure-fire way to make sure that |
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39 you've written portable code, here's a list of problems that have been |
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40 found and fixed in the tests. Another, more comprehensive list may be |
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41 found in the GNU Autoconf manual, online here: |
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42 |
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43 http://www.gnu.org/software/autoconf/manual/html_node/Portable-Shell.html |
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44 |
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45 sh: |
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46 |
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47 The Bourne shell is a very basic shell. /bin/sh on Linux is typically |
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48 bash, which even in Bourne-shell mode has many features that Bourne shells |
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49 on other Unix systems don't have (and even on Linux /bin/sh isn't |
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50 guaranteed to be bash). You'll need to be careful about constructs that |
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51 seem ubiquitous, but are actually not available in the least common |
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52 denominator. While using another shell (ksh, bash explicitly, posix shell, |
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53 etc.) explicitly may seem like another option, these may not exist in a |
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54 portable location, and so are generally probably not a good idea. You may |
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55 find that rewriting the test in python will be easier. |
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56 |
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57 - don't use pushd/popd; save the output of "pwd" and use "cd" in place of |
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58 the pushd, and cd back to the saved pwd instead of popd. |
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59 |
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60 - don't use math expressions like let, (( ... )), or $(( ... )); use "expr" |
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61 instead. |
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62 |
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63 grep: |
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64 |
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65 - don't use the -q option; redirect stdout to /dev/null instead. |
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66 |
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67 - don't use extended regular expressions with grep; use egrep instead, and |
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68 don't escape any regex operators. |
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69 |
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70 sed: |
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71 |
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72 - make sure that the beginning-of-line matcher ("^") is at the very |
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73 beginning of the expression -- it may not be supported inside parens. |
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74 |
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75 echo: |
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76 |
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77 - echo may interpret "\n" and print a newline; use printf instead if you |
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78 want a literal "\n" (backslash + n). |
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79 |
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80 false: |
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81 |
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82 - false is guaranteed only to return a non-zero value; you cannot depend on |
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83 it being 1. On Solaris in particular, /bin/false returns 255. Rewrite |
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84 your test to not depend on a particular return value, or create a |
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85 temporary "false" executable, and call that instead. |
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86 |
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87 diff: |
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88 |
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89 - don't use the -N option. There's no particularly good workaround short |
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90 of writing a reasonably complicated replacement script, but substituting |
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91 gdiff for diff if you can't rewrite the test not to need -N will probably |
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92 do. |